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

1. Current Condition: The coin has a condition of 95 (S/C-), indicating that it is in very good shape. This generally translates to a higher price compared to coins in lower condition.

2. Auction History:
- The average hammer price in previous auctions for coins with a similar condition (95) has been 300 euros (in the December 2021 auction and on other occasions).
- In the most recent auction with a condition of 95, the hammer price was 300 euros.

3. Starting Price and Average Hammer Price:
- The current starting price is 250 euros, which is reasonable given the price history.
- The average hammer price is 250.71 euros, suggesting that the hammer price could be in a similar range.

4. Price Trends: In previous auctions, hammer prices have fluctuated, but coins in condition 95 have reached hammer prices of up to 330 euros.

Based on these factors, an estimated maximum purchase price for this coin could be around 300-330 euros, as this is a price that has been reached in previous auctions for coins in similar conditions.

Therefore, I would recommend considering a maximum purchase price of 330 euros.