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 of 70 (MBC-), indicating that it is in relatively good shape, but not of the highest quality (FDC).

2. Auction History:
- The average hammer price in previous auctions for coins with a similar condition (70) has been approximately 41.5 euros (average of the hammer prices from auctions with condition 70).
- In past auctions, hammer prices for coins with condition 70 have ranged between 32 and 71 euros.

3. Price Trends:
- The average starting price has been 38.44 euros, and the average hammer price has been 52.39 euros. This suggests that buyers are willing to pay more than the starting price in most cases.

4. Recent Estimates: In recent auctions, hammer prices of up to 66 euros have been seen for coins with condition 70.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 60 to 70 euros, considering that the condition is good and there has been demonstrated interest in the past for similar coins.

Therefore, a reasonable estimated maximum purchase price could be 70 euros.