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

1. Condition: The coin to be auctioned has a condition of 95 (S/C-), indicating that it is in very good shape. This generally increases its value compared to coins with lower conditions.

2. Previous Prices: By looking at the hammer prices from previous auctions, we can see that:
- In 2021, a coin with a condition of 95 was sold for 260 euros.
- In 2022, a coin with a condition of 90 was sold for 190 euros.
- In 2018, a coin with a condition of 85 was sold for 65 euros.

3. Average Hammer Price: The average hammer price for similar coins is 115.56 euros, but since the condition of the coin in question is higher, we can expect the hammer price to be higher.

4. Starting Price: The starting price is 250 euros, suggesting that the seller has high expectations for this auction.

5. Sales Trends: The coin has been auctioned 13 times, of which it has sold 10 times. This indicates a consistent interest in this coin.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 250 to 300 euros, considering that the condition is high and there are precedents of successful sales at higher prices. However, since the starting price is 250 euros, it is likely that the hammer price will not significantly exceed this value unless there is active competition among bidders.

Therefore, a reasonable maximum purchase price could be approximately 280 euros.