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

1. Current Condition: The coin has a condition of 75 (MBC), which indicates that it is in relatively good shape, although it is not of the highest quality (FDC).

2. Previous Auction Prices: By looking at the auction prices of coins with similar conditions (around 75-85), we can see that:
- In 2022, a coin with a condition of 85 was auctioned for 280 euros.
- In 2020, a coin with a condition of 85 was auctioned for 320 euros.
- In 2020, a coin with a condition of 80 was auctioned for 180 euros.

3. Average Auction Price: The average auction price for this coin is 239.4 euros, which is also a good indicator.

4. Starting Price: The starting price is 180 euros, suggesting that the seller has moderate expectations.

Given that the condition of the coin is 75 and considering the previous auction prices, an estimated maximum purchase price could be in the range of 200 to 280 euros. However, since the condition is not the best, a more conservative price could be around 240 euros.

Maximum Purchase Estimate: 240 euros.