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

1. Current Condition: The coin has a condition of 75 (VF), which indicates that it is in fairly good shape, but not the best possible condition.

2. Historical Prices:
- In the past, the coin has reached auction prices of up to 347.7 euros in an auction with a condition of 90.
- Other auction prices have varied, with a range from 60 euros to 260 euros in similar conditions.

3. Average Auction Price: The average auction price for this coin is 163.3 euros, which can serve as a good indicator of the expected value.

4. Starting Price: The current starting price is 25 euros, suggesting that there is considerable room for the final price to be higher.

5. Auction Trends: Since the coin has sold every time it has been auctioned, this indicates a steady demand.

Based on these factors, an estimated maximum purchase price could be in the range of 150 to 200 euros, considering that the current condition is 75 and the average auction price is 163.3 euros. However, given that there are examples of higher auction prices in better conditions, a reasonable maximum purchase price could be approximately 200 euros.