To estimate a maximum purchase price for the coin in question, we can analyze the provided data, including the auction history and the current condition of the coin.

1. Current Condition: The coin has a condition rating of 75 (VF), indicating that it is in an acceptable state, but not among the best conditions.

2. Price History:
- The average hammer price for similar coins is 615.24 euros.
- In the past, hammer prices for coins with a similar condition (75) have varied, with the highest being 600 euros and the lowest 196.43 euros.

3. Starting Price: The starting price is 100 euros, which is relatively low compared to the average hammer price.

4. Sales Trends: Out of the 10 times this coin has been auctioned, it has sold 8 times, indicating good demand.

5. Estimation: Given that the average hammer price is significantly higher than the starting price, and considering that the condition is 75, a reasonable hammer price could be in the range of 300 to 600 euros, based on the price history.

Taking all these factors into account, an estimated maximum purchase price for this coin could be around 500 euros. This reflects a balance between the current condition, the price history, and the demand observed in previous auctions.