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

1. Current Condition: The coin has a condition rating of 80 (MS+), 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 coins with a similar condition (80) has been approximately 130-140 euros in several previous auctions.
- In recent auctions, we have seen hammer prices reaching up to 280 euros for coins with a condition of 80.

3. Starting Price and Average Hammer Price:
- The current starting price is 75 euros, which is reasonable given the history of starting and hammer prices.
- The average hammer price for this coin has been 142.39 euros, suggesting that buyers are willing to pay more than the starting price.

4. Recent Trends: In the most recent auctions, hammer prices have shown an increase, which could indicate a rising trend in interest for this coin.

Based on these factors, an estimated maximum purchase price could be in the range of 200 to 250 euros. This range takes into account the hammer price history for coins of similar condition and the recent market trend.