To estimate a maximum purchase price for the coin in question, we can 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 increases its value compared to coins in lower conditions.

2. Current and Previous Prices: The current starting price is 150 euros. In previous auctions, we have seen hammer prices that vary, but there are examples of hammer prices exceeding 200 euros, especially for coins in similar conditions.

3. Price Trends: The average hammer price for similar coins is 101.18 euros, but there are examples of auctions that have reached up to 270 euros. This suggests that there is significant potential for this coin to sell at a higher price.

4. Auction History: The coin has been auctioned 61 times, with an 87% sell-through rate (53 out of 61). This indicates a consistent interest in this coin, which may influence its price.

5. Comparison with Previous Prices: In recent auctions, coins with similar conditions have reached hammer prices of 240 euros (in March 2023) and 270 euros (in November 2020).

Taking all these factors into account, an estimated maximum purchase price for this coin could be around 250-300 euros. This is based on the auction price history and the good condition of the coin. However, the final price will depend on the competition in the auction and the interest from other buyers.