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

1. Current Condition: The coin has a condition rating of 80 (MS+). This is an important factor, as coins in better condition tend to reach higher prices.

2. Auction History:
- The average hammer price in previous auctions is 47.27 euros.
- It has been auctioned 119 times, of which 99 have sold, indicating good demand.
- In previous auctions, hammer prices for coins with similar conditions (around 80) have varied, but some have reached prices of up to 100 euros or more.

3. Starting Prices and Estimates:
- The current starting price is 25 euros, which is relatively low compared to the average hammer price.
- The average starting price in the past has been 31 euros, suggesting that the current starting price could be attractive to buyers.

4. Recent Trends:
- In the most recent auctions, hammer prices have shown a trend of being higher, especially for coins in good condition.

Based on these factors, an estimated maximum purchase price for this coin could be between 80 and 120 euros, considering that the condition is good and there is a history of hammer prices that supports this estimate.

Therefore, a reasonable maximum purchase price could be 100 euros.