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

1. Current Condition: The coin has a condition rating of 75 (MBC), indicating that it is in relatively good shape, but not among the highest quality.

2. Historical Prices: Looking at previous auction results, we can see that the coin has reached hammer prices of up to 320 euros in past auctions, although this was under higher condition ratings (such as 95).

3. Average Hammer Price: The average hammer price for this coin is 145.06 euros, which gives us an idea of what buyers are willing to pay on average.

4. Current Starting Price: The starting price is 120 euros, which may influence buyer interest.

5. Sales Trends: The coin has been sold in 36 out of 39 auctions, indicating good demand.

Given that the coin's condition is 75 and considering previous hammer prices, an estimated maximum purchase price could be in the range of 180 to 220 euros. This is based on the fact that, although the condition is not the highest, there is a history of hammer prices suggesting that buyers are willing to pay more for coins in similar conditions.

Therefore, an estimated maximum purchase price could be 200 euros.