To estimate a maximum purchase price for the coin in question, we can consider 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 in lower condition.

2. Auction History:
- The average hammer price in previous auctions is 52.25 euros.
- The last auction for this coin was hammered at 50 euros, suggesting that interest in the coin remains steady.
- Previous auctions show hammer prices that vary, but overall, prices have been increasing, especially for coins in better condition.

3. Starting Price and Average Starting Price:
- The current starting price is 50 euros, which is a good starting point.
- The average starting price of 38.62 euros suggests that the current starting price is a bit higher than average, which may indicate demand.

4. Price Trends:
- Observing previous hammer prices, there is an increase in prices as the condition improves. The last auction with a condition of 80 was hammered at 50 euros, indicating that this could be a good benchmark.

Based on these factors, an estimated maximum purchase price could be between 60 and 70 euros. This is because, although the starting price is 50 euros, the good condition and price history suggest there is room for a higher bid, especially if there is interest in the coin.

Therefore, a reasonable maximum purchase price could be 65 euros.