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

1. Current Condition: The coin has a condition rating of 80 (MBC+), 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 this coin in the past is 494.09 euros.
- In previous auctions, hammer prices have varied, but there are examples of sales exceeding 700 euros, especially in similar or better conditions.

3. Starting Price and Average Starting Price:
- The current starting price is 300 euros, which is slightly higher than the average starting price of 250.31 euros. This may indicate an expectation of a higher hammer price.

4. Recent Trends: In the most recent auctions, there have been sales reaching significantly high prices, such as 2400 euros in a previous auction with a condition of 95.

5. Estimation Based on Condition and Previous Prices: Given that the coin's condition is 80 and considering that in the past it has reached hammer prices of up to 750 euros in similar conditions, we can estimate that the maximum purchase price could be in a high range.

### Final Estimation
Taking all these factors into account, an estimated maximum purchase price for this coin could be 700 to 800 euros. This is based on the hammer price history and the current condition of the coin.