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

1. Coin 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. Starting Price: The starting price is 900 euros, suggesting that the seller expects a considerably high price.

3. Auction History: By observing previous hammer prices for coins with similar conditions (95 and 90), we can see that they have reached hammer prices that vary significantly. For example:
- In December 2019, a coin with a condition of 95 was sold for 320 euros.
- In July 2019, another coin with a condition of 95 sold for 370 euros.
- In December 2021, a coin with a condition of 95 was auctioned for 1100 euros.

4. Price Trends: The average hammer price for similar coins is 92.21 euros, but this may not adequately reflect the value of a coin in as good condition as the one being auctioned.

5. Market Expectations: Given that there are 2 auctions scheduled in the coming days, this may increase competition and, therefore, the final price.

Taking all these factors into account, an estimated maximum purchase price could be between 800 and 1200 euros, considering that the condition is high and there is a history of hammer prices that supports this estimate. However, given the starting price of 900 euros, it is likely that the final price will be closer to this upper range.

Therefore, a reasonable maximum purchase price could be 1200 euros.