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

1. Current Condition: The coin has a condition of 75 (MBC), which indicates that it is in a medium-low state. This generally affects the price, as coins in better condition tend to reach higher prices.

2. Auction History:
- The average hammer price in previous auctions is 87.58 euros.
- The condition of the coins auctioned in the past varies, but there are examples of coins with similar conditions that have sold for prices ranging from 20 to 240 euros, depending on the condition and demand at that time.

3. Starting Price: The current starting price is 15 euros, which is relatively low compared to the average hammer price.

4. Price Trends: Observing the hammer prices of coins with similar conditions, it seems that the price range can vary quite a bit. For example, coins with conditions from 70 to 80 have reached hammer prices between 20 and 50 euros on several occasions.

5. Supply and Demand: Since there are no auctions scheduled in the coming days, this could influence demand and, therefore, the price.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 40 to 60 euros. This is based on the historical hammer prices of coins with similar conditions and the average hammer price observed. However, it is important to note that the final price may vary depending on the competition in the auction and the specific demand at that time.