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 relatively 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:
- Coins with a condition of 70 have had auction prices ranging from 18 to 30 euros.
- Coins with a condition of 80 have reached auction prices of up to 95 euros.
- Coins with a condition of 90 have been auctioned for 190 euros.

3. Average Auction Price: The average auction price for this coin is 129.31 euros, suggesting that, in general, coins of this reference tend to sell for relatively high prices.

4. Starting Price and Average Starting Price: The starting price is 25 euros, and the average starting price is 92.97 euros. This indicates that the market expects the coin to sell for a price higher than the starting price.

5. Recent Trends: In the most recent auctions, auction prices have shown a trend of increasing, especially for coins in good condition.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 100 to 150 euros, considering that the condition is good and that the average auction price is significantly higher than the starting price. However, since the market can be volatile, it is advisable to keep an eye on the auction and adjust the bid accordingly.