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

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

2. Auction History:
- The average hammer price in previous auctions is 54 euros.
- The coin has been auctioned 13 times, of which it has sold 10 times, indicating good demand.
- Previous hammer prices varied, but there are examples of hammer prices reaching up to 96 euros in similar conditions.

3. Starting Price and Estimated Prices:
- The current starting price is 20 euros, which is relatively low compared to the average hammer price.
- The average starting price in previous auctions is 60.64 euros, suggesting that the current starting price may be underestimated.

4. Price Trends:
- In the most recent auction, the estimated price was 90 euros, and the hammer price was 85 euros, indicating potential for price increase.

Considering all these factors, an estimated maximum purchase price for this coin could be in the range of 80 to 100 euros, taking into account its good condition and the price history in previous auctions. A price of 90 euros could be a reasonable target, given that it has been reached in recent auctions.

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 30 (BC+), indicating that it is not in very good shape. This will negatively affect its value compared to coins in better condition.

2. Auction History:
- The average hammer price for similar coins in the past is 502.8 euros.
- The coin has been auctioned 19 times, of which it has sold 11 times. This suggests that there is moderate interest in the coin.
- Previous hammer prices have varied significantly, with some reaching high prices (for example, 1200 euros in 2013 and 1700 euros in 2020), but there are also lower prices (such as 50 euros in 2014 and 50 euros in 2022).

3. Starting Price: The current starting price is 40 euros, which is relatively low compared to the average hammer price.

4. Price Trends: Hammer prices have fluctuated, but there are examples of coins in similar conditions that have reached hammer prices of up to 400 euros in recent auctions.

Given that the condition of the coin is low and considering the price history, an estimated maximum purchase price could be in the range of 150 to 250 euros. This is based on the fact that, although the coin has a history of high prices, its current state limits its value.

Therefore, a reasonable maximum purchase price could be 200 euros.

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

1. Current Condition: The coin has a condition of 75 (MBC), indicating that it is in quite good shape. This can positively influence its price.

2. Auction History:
- It has been auctioned 8 times in the past, of which it has sold 5 times. This suggests there is consistent interest in the coin.
- The average starting price in previous auctions is 69.97 euros, and the average hammer price is 91.46 euros. This indicates that, on average, similar coins have reached hammer prices that exceed the starting price.

3. Previous Prices:
- In 2013, the coin sold for 122.09 euros, which is a notably high price.
- In 2014, with a condition of 75, the starting price was 50.56 euros, but no hammer price was reported.
- In 2015, it sold for 156.34 euros, which is also a high price.
- In 2017, the starting price was 75 euros, but no hammer price was reported.

4. Price Trends: Hammer prices have varied, but there are examples of high prices in the past, suggesting that the coin may have significant value in the market.

Based on these factors, an estimated maximum purchase price could be set in a range that considers both the average hammer price and the highest prices reached in previous auctions.

Given that the condition is good and there is a history of high prices, a reasonable maximum purchase price could be:

Estimated maximum purchase price: 130 - 150 euros.

This range takes into account the interest in the coin, its condition, and previous hammer prices.

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 75 (MBC), indicating that it is in fairly good shape, but not the best possible condition.

2. Auction History:
- The average hammer price in previous auctions is 63.37 euros.
- It has been auctioned 29 times, of which 13 have sold, indicating a sell-through rate of 44.83%. This suggests there is interest in the coin, but it does not always sell.

3. Previous Prices:
- In past auctions, hammer prices have varied. For example, in 2016 it sold for 120 euros in a condition of 90, and on other occasions, it has ranged between 60 and 80 euros in conditions similar to the current one.

4. Starting Price: The starting price is 50 euros, which is a good starting point, but the hammer price is usually higher.

5. Recent Trends: In recent auctions, hammer prices have been in the range of 70 to 80 euros for similar conditions.

Based on these factors, an estimated maximum purchase price could be between 70 and 80 euros, considering that the condition is good and there is a history of hammer prices that supports this estimate. Therefore, a reasonable maximum purchase price could be 80 euros.