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

1. Current Condition: The coin has a condition rating of 85 (ebc-), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Current Starting Price and Previous Prices: The current starting price is 90 euros. In previous auctions, the average hammer price has been approximately 92.97 euros, suggesting that coins of this reference tend to sell close to their starting price or slightly above.

3. Sales History: Out of the 41 times this coin has been auctioned, it has sold 37 times, indicating good demand. Additionally, the highest hammer price in the past was 260 euros, although this may have been for a coin in better condition.

4. Recent Trends: In the most recent auctions, hammer prices have varied, but there are examples of similar coins that have sold for prices exceeding 100 euros, especially those with higher conditions.

Based on these factors, an estimated maximum purchase price could be between 100 and 120 euros. This is because, although the starting price is 90 euros, the good condition and sales history suggest that buyers may be willing to pay a bit more.

Therefore, a reasonable maximum purchase price could be 110 euros.