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 relatively good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History:
- The average hammer price for similar coins has been 59.58 euros.
- In the past, hammer prices have varied significantly, ranging from 20 euros to 200 euros, depending on the condition and demand at the time of the auction.

3. Starting Price: The starting price is 30 euros, which can influence the final price, as hammer prices are often higher than the starting price.

4. Recent Trends: In the most recent auctions, hammer prices for coins with similar conditions have been in the range of 40 to 60 euros.

Based on these factors, an estimated maximum purchase price for this coin could be between 70 and 90 euros, considering that the condition is good and that the price history shows that coins in similar conditions have reached higher prices in the past.

Therefore, a reasonable maximum purchase price could be 80 euros.