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 similar coins has been 96.89 euros.
- In the past, hammer prices have varied significantly, ranging from 24 euros to 420 euros, depending on the condition and other factors.

3. Starting Price and Previous Sales:
- The current starting price is 45 euros, and there have been 14 previous auctions with 9 sales, indicating moderate interest in this coin.
- The average starting price of 48.2 euros suggests that the current starting price is reasonable.

4. Price Trends:
- The highest recorded auction price was 420 euros for a coin with a condition of 85, suggesting significant potential for high prices in well-preserved coins.

Given all this, an estimated maximum purchase price could be in the range of 100 to 120 euros, considering that the condition of this coin is good and that interest in similar coins has shown hammer prices that can be quite high.

Therefore, a reasonable maximum purchase price could be 110 euros.