To estimate a maximum purchase price for the coin in question, we can analyze the provided data, including the starting price, current condition, and hammer prices from previous auctions.

1. Condition: The coin has a condition rating of 75 (MBC), indicating that it is in fairly good shape. This suggests that its value should be in the mid-high range of previous auctions.

2. Previous hammer prices: By looking at the hammer prices from previous auctions for coins with a similar condition (75), we can see that:
- In several auctions, the hammer prices have ranged from 32 to 155.83 euros.
- The average hammer price in the past has been 64.35 euros.

3. Starting price: The current starting price is 60 euros, which is reasonable given the price history.

4. Trends: Given that there have been 18 previous auctions and 6 of them resulted in sales, this indicates moderate interest in the coin. However, the fact that 12 did not sell may suggest that the market is a bit volatile for this particular coin.

5. Estimation: Based on the average hammer price of 64.35 euros and considering that the condition is good, a maximum purchase price could be in the range of 80 to 100 euros. This is because buyers are often willing to pay a little more for coins in good condition.

Therefore, an estimated maximum purchase price for this coin could be 85 euros. This reflects a balance between market interest, the condition of the coin, and previous hammer prices.