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 75 (VF), indicating that it is in fairly good shape, but not among the highest qualities.

2. Auction History:
- The average hammer price in previous auctions is 83.34 euros.
- It has been auctioned 18 times, of which 14 have sold, indicating good demand.
- Previous hammer prices varied, but there are examples of hammer prices exceeding 100 euros, such as in 2023 where it sold for 91 euros and in 2016 where it sold for 112.05 euros.

3. Starting Price: The starting price is 40 euros, which is relatively low compared to previous hammer prices.

4. Price Trends: The average starting price in previous auctions is 66.81 euros, suggesting that buyers are willing to pay more than the starting price.

5. Future Projections: In the upcoming auction, the estimated price is 160 euros, indicating expectations that the value of the coin may increase.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 90 to 120 euros. This is based on the history of hammer prices and the current condition of the coin. A price of 100 euros could be a reasonable target, as it falls in the middle of this range and aligns with buyer expectations in previous auctions.