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

1. Condition: The coin has a condition rating of 95 (EF+), indicating that it is in very good shape. This generally increases its value compared to coins in lower conditions.

2. Starting price and previous prices: The current starting price is 2500 euros. In previous auctions, the hammer price has varied, but there are examples of hammer prices exceeding 2000 euros, even reaching up to 3400 euros in the past.

3. Price trends: The average hammer price in previous auctions is 1680.68 euros, but there are several cases where the hammer price has been significantly higher, especially for coins in similar conditions.

4. Demand and supply: The coin has been auctioned 28 times in the past, with an 82% sell-through rate (23 out of 28). This suggests that there is consistent interest in this coin, which may influence the price.

5. Recent hammer prices: In the most recent auctions, hammer prices have been in the range of 1700 to 1800 euros, indicating that interest and value for the coin remain strong.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 2500 to 3000 euros, considering that the starting price is 2500 euros and that the coin's condition is high. However, if there is strong competition in the auction, the price could exceed 3000 euros, especially if bidders are willing to pay more for a coin in such good condition.

Therefore, a reasonable maximum purchase price could be 3000 euros.