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

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

2. Starting price: The starting price is 1300 euros, which sets a baseline for the auction.

3. Price history: By observing previous hammer prices for coins with similar conditions (95 and 100), we can see that hammer prices have varied. For example:
- In previous auctions, coins with a condition of 95 have reached hammer prices of up to 335 euros (in 2014) and 300 euros (in 2022).
- Coins with a condition of 100 have reached hammer prices of up to 1900 euros (in 2022).

4. Price trends: The average hammer price for similar coins is 684.3 euros, suggesting that the hammer price may be considerably lower than the starting price in some cases.

5. Supply and demand: The coin has been auctioned 31 times in the past, with 22 sales, indicating moderate interest in the coin. However, the fact that there have been 9 occasions where it did not sell may indicate that the starting price is an important factor.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 800 to 1200 euros, depending on the competition in the auction and the interest of other bidders. Given that the starting price is 1300 euros, bidders may be willing to pay a little more, but it is likely that the hammer price will not significantly exceed the starting price, especially if there are other attractive lots in the same auction.

Therefore, a reasonable maximum purchase price could be 1000 euros.