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

1. Current Condition: The coin has a condition of 90 (EF), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Current Auction Price and Previous Prices: The current auction price is 4000 euros. In previous auctions, we have seen hammer prices that vary, but there are examples of coins with similar conditions that have sold for prices above 4000 euros. For instance, at the auction on 2020-03-12, a coin with a condition of 95 sold for 4000 euros, and in other auctions, coins with conditions of 85 and 90 have reached hammer prices of up to 3600 euros.

3. Price Trends: The average hammer price for similar coins is approximately 2934.31 euros, but there are examples of coins that have reached significantly higher hammer prices, especially in higher conditions.

4. Demand and Supply: The coin has been auctioned 42 times, with a sell-through rate of 80.95% (34 out of 42). This suggests that there is consistent interest in this coin, which may influence the price.

5. Price Projections: Given that the condition is good and considering previous hammer prices, an estimated maximum purchase price could be in the range of 5000 to 6000 euros, especially if there is interest in the auction.

Final Estimate: Based on all these factors, an estimated maximum purchase price for this coin could be 5500 euros. This reflects a balance between the condition, previous hammer prices, and market demand.

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

1. Current Condition: The coin is in a condition of 90 (EF), indicating that it is in quite good shape. This generally translates to a higher price compared to coins in lower conditions.

2. Starting Price and Previous Prices: The current starting price is 4000 euros. In previous auctions, the average hammer price has been approximately 2934.31 euros, suggesting that the starting price may be a bit optimistic, but not unusual for a coin in good condition.

3. Price Trends: By observing previous hammer prices for coins with similar conditions (around 85-95), we can see that hammer prices have varied, but generally, coins in EF condition tend to reach higher prices. For example, in recent auctions, coins with a condition of 85 have reached hammer prices of up to 3600 euros.

4. Supply and Demand: The coin has been auctioned 42 times, with a sell-through rate of 81% (34 out of 42). This indicates good demand, which can push the price upwards.

5. Comparison with Previous Prices: In previous auctions, coins with similar conditions have reached hammer prices ranging from 2200 to 8000 euros, depending on the condition and demand at that time.

Taking all these factors into account, an estimated maximum purchase price for this coin could be around 5000 euros. This price reflects a balance between the current condition, market price trends, and the demand observed in previous 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 of 70 (VF-). This is an important factor, as coins in better condition tend to reach higher prices.

2. Auction History:
- It has been auctioned 6 times in the past, of which 5 have sold. This indicates a consistent interest in the coin.
- The average starting price in previous auctions is 365.25 euros, and the average hammer price is 1137.57 euros. This suggests that, although the current starting price is 60 euros, the actual value of the coin may be significantly higher.

3. Previous Prices:
- Previous hammer prices varied considerably, with a maximum price of 3684.58 euros for a coin in condition 107.
- The last auction in 2017 reached a hammer price of 1200 euros, although the condition is not specified.

4. Market Trends: Given that the current starting price is 60 euros, which is significantly lower than the average starting and hammer prices, this could indicate a buying opportunity.

Based on these factors, an estimated maximum purchase price could be in the range of 300 to 600 euros, considering that the coin's condition is 70 and that interest in it has been consistent in the past. This allows for a margin for potential appreciation in value in future auctions.

Therefore, a reasonable maximum purchase price could be 500 euros.