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

1. Condition of the coin: The coin has a condition rating of 90 (EF), 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 is 59.73 euros.
- In previous auctions, we have seen hammer prices that varied significantly, but there are examples of coins in similar conditions that have sold for higher prices, such as 270 euros in a previous auction with a condition of 100.

3. Starting price and estimates:
- The current starting price is 60 euros, which is slightly higher than the average starting price of 45.53 euros. This suggests that the seller has expectations of a higher price due to the good condition.
- The estimated price of 110 euros in a previous auction with a condition of 90 is also relevant.

4. Sales trends: The coin has been auctioned 37 times, of which 31 have sold. This indicates good demand and consistent interest in this reference.

Taking all these factors into account, an estimated maximum purchase price could be around 100-120 euros. This is based on the good condition of the coin and the previous hammer prices for coins in similar conditions. However, it is important to consider that the final price may vary depending on the competition in the auction and the interest of other buyers.