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 95 (S/C-), indicating that it is in very good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History:
- The average hammer price for similar coins in the past is approximately 733.94 euros.
- In previous auctions, coins with a similar condition (95) have reached hammer prices of up to 1100 euros (as seen in the auction on December 16, 2021, and May 27, 2024).

3. Starting Price: The current starting price is 900 euros, suggesting that the seller has expectations of a relatively high hammer price.

4. Price Trends: The price trend for coins of similar condition has shown an increase in hammer prices in recent auctions, which could indicate a growing market for this coin.

Based on these factors, an estimated maximum purchase price could be in the range of 1000 to 1200 euros, considering that the condition is high and there have been precedents for hammer prices in that range. However, since the starting price is 900 euros, it is likely that buyers will be willing to bid up to that upper range, especially if there is interest in the coin.

Therefore, an estimated maximum purchase price could be 1100 euros.