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 90 euros, which sets a baseline for the auction.

3. Price History: By looking at previous auction prices for coins with similar conditions (95 and 100), we can see that they have reached hammer prices that vary significantly. For example:
- In 2019, a coin with a condition of 95 was auctioned for 95 euros.
- In 2018, another coin with a condition of 100 was auctioned for 95 euros.
- In 2024, it is estimated that a coin with a condition of 95 could reach a hammer price of 140 euros.

4. Price Trends: The average hammer price for similar coins is 62.53 euros, but since this coin has a higher condition, it is reasonable to expect its hammer price to be above this average.

5. Supply and Demand: The coin has been auctioned 67 times in the past, of which 60 have successfully sold. This suggests there is consistent interest in this coin, which could drive up its price.

Taking all these factors into account, an estimated maximum purchase price could be between 120 and 150 euros, considering the good condition and the auction price history for similar coins. This would allow for competitive bidding in the auction without exceeding a reasonable limit based on historical data.