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

1. 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 this coin is 21.65 euros.
- In previous auctions, we have seen hammer prices that vary, but some relevant examples are:
- In 2020, a coin with a similar condition sold for 46 euros.
- In 2020, another coin with a condition of 100 sold for 40 euros.
- In 2021, a coin with a condition of 95 sold for 30 euros.

3. Starting Price and Estimates:
- The current starting price is 15 euros, and the estimated price is 35 euros.
- The average starting price in previous auctions is 13.23 euros, suggesting that the current starting price is reasonable.

4. Recent Trends:
- In the most recent auctions, hammer prices have shown a trend of being higher, especially for coins in good condition.

Based on these factors, an estimated maximum purchase price could be between 40 and 50 euros, considering that the condition is high and there is a history of hammer prices that supports this figure. However, since the market can be volatile, it is advisable to keep an eye on the auction and adjust the bid accordingly.