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

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

2. Historical Prices: By looking at previous auction prices for coins with similar conditions, we can see that the average auction price for conditions ranging from 70 to 80 has been in a range of approximately 55 to 110 euros.

3. Average Auction Price: The average auction price for this particular coin is 126.06 euros, suggesting that there is significant interest in this coin.

4. Recent Trends: In the most recent auctions, the hammer prices have varied, but there are examples of auctions reaching up to 850 euros for high-condition coins (95) and lower prices for conditions ranging from 70 to 80.

5. Starting Price and Average Starting Price: The starting price is 45 euros, and the average starting price is 73.47 euros. This indicates that the market is willing to pay more than the starting price on many occasions.

Based on these factors, an estimated maximum purchase price for the coin in question could be in the range of 150 to 200 euros. This range takes into account the current condition, previous auction prices, and general interest in the coin. However, it is important to note that the final price may vary depending on competition in the auction and demand at the time.