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

1. Current Condition: The coin has a condition rating of 75 (MBC), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History:
- The average hammer price for similar coins in the past is 28.43 euros.
- The last auction with a known hammer price for a coin of similar condition (80) was 25 euros, suggesting that the market is willing to pay in that range.

3. Starting Prices and Estimates:
- The current starting price is 25 euros, and the average starting price in the past has been 21.93 euros. This indicates that the current starting price is reasonable and aligns with historical data.

4. Price Trends:
- In previous auctions, hammer prices have varied, but there are examples of coins in similar conditions that have reached hammer prices of up to 95 euros (in the case of a coin with a condition of 95).

5. Supply and Demand: Since there are no scheduled auctions in the coming days for this coin, there could be increased demand at the time of the current auction.

Taking all these factors into account, an estimated maximum purchase price for this coin could be in the range of 40 to 60 euros. This is based on the current condition, price history, and market trends. However, it is important to remember that the final price may vary depending on competition in the auction and the interest of other buyers.