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

1. Current Condition: The coin has a condition rating of 75 (VF), indicating that it is in fairly good condition.

2. Previous Auction Prices: The average auction price for this coin is 187.33 euros. This suggests that, in general, buyers are willing to pay significantly more than the starting price.

3. Auction Prices for Similar Conditions: By observing the auction prices of coins with similar conditions (75 and 80), we can see that they have reached auction prices of up to 260 euros in recent auctions.

4. Auction Trends: The coin has been auctioned 51 times, of which 44 have been sold. This indicates good demand and consistent interest in the coin.

5. Starting Price: The starting price is 80 euros, which is relatively low compared to the average auction price.

Based on these factors, an estimated maximum purchase price could be in the range of 200 to 260 euros, considering that the highest auction price in recent sales for similar conditions has been 260 euros.

Therefore, a reasonable maximum purchase price could be 250 euros. This allows for some competition in the auction and aligns with previous auction prices.