To estimate a maximum purchase price for the coin in question, let's consider several factors:

1. Condition: The coin has a condition rating of 110 (FDC), indicating that it is in exceptional condition. This generally increases its value compared to coins with lower conditions.

2. Previous auction prices:
- In 2018, the coin was auctioned with a starting price of 90,000 euros and sold for 90,000 euros, with a condition rating of 100.
- In 2024, the starting price was 150,000 euros, with an estimated price of 300,000 euros and a final sale of 240,000 euros, also with a condition rating of 100.

3. Average hammer price: The average hammer price for previous auctions is 165,000 euros, which can serve as a reference.

4. Current starting price: The current starting price is 125,000 euros, which is lower than the average hammer price of previous auctions.

Given that the coin has a superior condition (110) and considering the price history, an estimated maximum purchase price could be set in a range above the current starting price, but it should also take into account the average hammer price.

Estimation: A reasonable maximum purchase price could be between 200,000 and 250,000 euros, given that the condition is excellent and interest in the coin may be high. However, the final price will depend on the competition in the auction and the interest of collectors.