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 fairly good shape, but not the best possible condition.

2. Auction History:
- The average hammer price for similar coins has been 32.73 euros.
- In previous auctions, coins with a similar condition (75) have had hammer prices that varied, with examples selling for 15 euros (in 2020) and up to 65 euros (in 2020 with a condition of 85).

3. Starting Price: The starting price is 15 euros, which may attract more bidders.

4. Price Trends: Observing the hammer prices of coins with similar conditions, it seems that the price range can fluctuate between 15 and 65 euros, depending on demand and other market factors.

5. Estimated Price: In previous auctions, the estimated price for coins with a condition of 75 has been around 20 to 30 euros.

Based on these factors, an estimated maximum purchase price for this coin could be around 40 euros. This is based on the hammer price history and the current condition, suggesting that there is potential for the coin to reach a higher price at auction.