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

1. Current Condition: The coin has a condition of 75 (MBC), indicating that it is in average condition. This generally affects the price, as coins in better condition tend to reach higher prices.

2. Auction History:
- The average starting price for similar coins is 232.79 euros, and the average hammer price is 627.43 euros.
- In the past, coins with a similar condition (75) have been auctioned at prices that varied significantly, from 40 euros to 800 euros, depending on demand and other factors.

3. Price Trends:
- In recent auctions, hammer prices have reached up to 800 euros for coins with similar conditions.
- The last auction of a coin with a condition of 85 reached a hammer price of 800 euros, suggesting that there is an active and potentially growing market for these coins.

4. Starting Price: The starting price of 80 euros is relatively low compared to the average starting price of similar coins, which could indicate a good buying opportunity.

Taking all these factors into account, an estimated maximum purchase price for this coin could be between 300 and 400 euros. This is based on the auction price history for coins of similar condition and the potential for appreciation in the market. However, the final price will depend on the competition in the auction and the specific demand at that time.