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

1. Coin Condition: The coin has a condition rating of 80 (MBC+). This is an important factor, as coins in better condition tend to fetch higher prices at auctions.

2. Starting Price and Previous Prices: The current starting price is 80 euros, and the average hammer price in previous auctions is 206.25 euros. This suggests that, in general, coins of this reference tend to sell for a significantly higher price than their starting price.

3. Auction History: In the auction history, there are examples of coins with similar conditions that have sold for prices that varied considerably. For instance, in previous auctions, coins with a condition of 85 have sold for prices around 210 euros, and some even higher.

4. Recent Trends: Looking at the most recent auctions, there is a pattern that coins with similar conditions have reached hammer prices that exceed the starting price. This suggests that there is active demand for this type of coin.

Based on these factors, an estimated maximum purchase price could be in the range of 200 to 250 euros. This is based on the average hammer price and the price history of coins with similar conditions.

Therefore, a reasonable estimated maximum purchase price for this coin could be approximately 220 euros.