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 very good shape. This generally translates to a higher price compared to coins in lower conditions.

2. Auction History:
- The average hammer price for similar coins in condition 90 has been 60.91 euros.
- In previous auctions, coins in condition 90 have sold for varying prices, but the last recorded hammer price was 240 euros, indicating a high selling potential for coins in this condition.

3. Starting Price and Average Starting Price:
- The current starting price is 60 euros, which is a good starting point, but the average starting price of 41.16 euros suggests that there may be competition keeping the price lower.

4. Demand and Supply: The coin has been auctioned 25 times, with a sell-through rate of 96% (24 out of 25), indicating a consistent interest in this coin.

5. Recent Trends: The last hammer price of 240 euros for a coin in condition 90 suggests that there is a market willing to pay more for coins in excellent condition.

Based on these factors, an estimated maximum purchase price could be in the range of 150 to 240 euros, considering that the highest recorded hammer price for a coin in similar condition was 240 euros. However, since the starting price is 60 euros, it is likely that the final hammer price will be closer to the average, so a reasonable maximum purchase price could be approximately 150 euros.