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

1. Current Condition: The coin has a condition rating of 75 (MBC), indicating that it is in relatively good shape. This can positively influence its price.

2. Auction History:
- The average hammer price in previous auctions is 120.49 euros.
- The coin has been auctioned 51 times, of which it has sold 42 times, indicating good demand.
- Previous hammer prices for coins with similar conditions (around 75) have varied, but there are examples of auctions reaching up to 200 euros (such as in the auction on 2019-10-17).

3. Starting Price and Average Starting Price:
- The current starting price is 60 euros, and the average starting price in previous auctions is 74.02 euros. This suggests that the starting price is reasonable and could attract bidders.

4. Recent Trends: In the most recent auctions, hammer prices have ranged from 70 to 150 euros for similar conditions.

Based on these factors, an estimated maximum purchase price could be in the range of 150 to 200 euros, considering that the coin is in good condition and has shown a hammer price history that supports this estimate.

Therefore, a reasonable maximum purchase price could be 180 euros.