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

1. 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 with lower conditions.

2. Auction History:
- The average hammer price for similar coins has been 114.28 euros.
- In previous auctions, hammer prices for coins with similar conditions (80) have varied, but there are examples where hammer prices have reached up to 135 euros (as in the auction on December 11, 2018).

3. Starting Price: The starting price is 60 euros, which is relatively low compared to previous hammer prices.

4. Recent Trends: In the most recent auctions, hammer prices have shown an increase, suggesting a positive trend in the coin's value.

Based on these factors, an estimated maximum purchase price could be in the range of 130 to 150 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 150 euros.