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 (MBC), which indicates that it is in fairly good shape, but not of the highest quality (FDC).

2. Previous Auction Prices: By looking at previous auction prices for coins with a similar condition (75-80), we can see that auction prices have varied. For example, in past auctions, coins with a condition of 75 have reached auction prices of up to 300 euros.

3. Average Auction Price: The average auction price for this coin is 204.35 euros, which gives us a good reference for what buyers are willing to pay.

4. Starting Price: The starting price is 120 euros, which is reasonable and may attract buyers.

5. Market Trends: Since the coin has been auctioned 206 times and has had a high sales percentage (195 out of 206), this indicates a consistent demand.

Based on these factors, an estimated maximum purchase price could be in the range of 250 to 300 euros, considering that the condition is good and there are precedents for auction prices in that range for similar coins.

Therefore, a reasonable maximum purchase price could be 280 euros.