To estimate a maximum purchase price for the coin in question, we can analyze the provided data:

1. Current starting price: 900 euros.
2. Average hammer price in previous auctions: 1437 euros.
3. Auction history: The coin has been auctioned 10 times and has sold in all of them, indicating good demand.
4. Previous hammer prices: The hammer prices have varied, but there are examples of sales exceeding 1000 euros, even reaching 1500 euros on some occasions.

Since there is no information about the current condition of the coin, it is difficult to make an accurate estimate. However, we can consider the following points:

- The average hammer price (1437 euros) suggests that buyers are willing to pay a price higher than the starting price.
- The trend of hammer prices in the past shows that, in general, prices have been quite high, especially in recent auctions.

Based on this information, an estimated maximum purchase price could be positioned in a range between the average hammer price and a bit more, considering that the starting price is 900 euros.

Therefore, an estimated maximum purchase price could be approximately 1600 euros. This is based on the trend of previous hammer prices and the consistent demand for the coin.

To estimate a maximum purchase price for the coin in question, we will consider several factors:

1. Current Condition: The coin has a condition rating of 85 (ebc-), indicating that it is in fairly good shape, but not the best possible condition. This may influence the price, as coins in better condition tend to fetch higher prices.

2. Current Starting Price and Previous Prices: The current starting price is 600 euros, and the average hammer price in previous auctions is 1437 euros. This suggests that, in general, coins of this reference tend to sell for a significantly higher price than their starting price.

3. Auction History: The auction history shows that on several occasions the coin has reached hammer prices that exceed the starting price. For example, in the 2020 auction, the hammer price was 1100 euros with a starting price of 450 euros. This indicates that there is considerable interest in this coin.

4. Price Trends: The average hammer price of 1437 euros is a good indicator of what buyers are willing to pay. However, given that the current condition is 85, it is reasonable to adjust this price downward.

5. Comparison with Previous Prices: The coin has had hammer prices that vary, but overall, the hammer prices have been in a range that suggests the price of 1437 euros is achievable, although it may not be reached in this specific auction due to the condition.

Taking all these factors into account, an estimated maximum purchase price could be around 1200-1300 euros. This reflects interest in the coin, but also considers its condition and the fact that the hammer price may vary depending on competition in the auction.

To estimate a maximum purchase price for the coin in question, we will consider several factors:

1. Current Condition: The coin has a condition rating of 80 (MS+), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Current Listing Price and Previous Prices: The current listing price is 800 euros. The average hammer price in previous auctions is 1035.94 euros, suggesting that coins of this reference tend to sell for above their listing price.

3. Historical Trends: Looking at the hammer prices from previous auctions, there are examples of similar coins that have sold for significantly higher prices, especially those with similar or better conditions. For instance, in a recent auction, a coin with a condition of 75 sold for 3900 euros, indicating a strong market for coins of this reference.

4. Price Estimates: The estimated price for this auction is 1700 euros, which also suggests that bidders are willing to pay more than the listing price.

Considering all these factors, an estimated maximum purchase price could be around 1500-1700 euros, as this aligns with previous price trends and the condition of the coin. However, it is important to remember that the final price may vary depending on the competition in the auction and the interest of collectors.

To estimate a maximum purchase price for the coin in question, we can analyze the provided data and consider several factors:

1. Current starting price: 1000 euros.
2. Auction history: The coin has been auctioned 5 times and has sold on all occasions, indicating a constant interest in the coin.
3. Average starting price: 880 euros, suggesting that the current starting price is above the historical average.
4. Average hammer price: 1740 euros, which is significantly higher than the current starting price.
5. Previous prices:
- In 2019, it was auctioned with a starting price of 1200 euros and sold for 2400 euros.
- In 2014, the starting price was 500 euros, but the hammer price was only 500 euros, indicating that there was not much interest.
- In 2013, the starting price was 900 euros and it sold for 1900 euros.
- In 2023, the starting price was 800 euros and it sold for 1200 euros, with a condition rating of 75.

Since there is no information about the condition of the current coin, it is difficult to make an accurate estimate. However, considering that the average hammer price is 1740 euros and that significant interest has been observed in previous auctions, we could estimate a maximum purchase price.

Taking into account the current starting price of 1000 euros and the auction history, a reasonable maximum purchase price could be in the range of 1800 to 2000 euros, assuming that the condition of the coin is at least acceptable and that interest in the coin remains.

Therefore, an estimated maximum purchase price could be 2000 euros.

To estimate a maximum purchase price for the coin in question, let’s consider the following factors:

1. Starting Price: 500 euros. This is the initial price set for the auction.
2. Auction History: The coin has been auctioned 2 times in the past, of which it has sold 1 time. This indicates moderate interest in the coin.
3. Average Starting and Hammer Price: The average starting price in the past is 270 euros, and the average hammer price is 650 euros. This suggests that, although the current starting price is higher, interest in the coin may lead to a higher hammer price.
4. Condition: There is no information about the current condition of the coin, which may make bidders more cautious. However, the previous hammer price of 70 euros for a coin with a condition of 20 suggests that interest may vary depending on the condition.
5. Previous Prices: In the last auction, the starting price was 40 euros, indicating that interest and the value of the coin have increased over time.

Given that the current starting price is 500 euros, which is significantly higher than the previous average starting price, and considering that the average hammer price is 650 euros, we could estimate that the maximum purchase price could be in a range between the starting price and the average hammer price.

Taking all these factors into account, an estimated maximum purchase price could be approximately 600 euros. This is based on historical interest and the potential for bidding, but it also considers the lack of information about the current condition, which could limit bidder interest.