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

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 72.19 euros.
- The coin has been auctioned 33 times, of which it has sold 22 times, indicating good demand.
- Previous hammer prices for coins with similar conditions (75) have reached up to 260 euros (in the case of the December 2020 auction).

3. Starting Price and Average Starting Price:
- The current starting price is 30 euros, which is quite low compared to the average hammer price and the average starting price (49.84 euros).

4. Price Trends:
- In previous auctions, hammer prices have varied, but there are examples of coins with similar conditions that have sold for significantly higher prices.

Based on these factors, an estimated maximum purchase price could be in the range of 80 to 120 euros. This is based on the historical hammer prices for coins of similar condition and the price trends in previous auctions.

Therefore, a reasonable maximum purchase price could be 100 euros.