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

1. Coin Condition: The coin has a condition rating of 95 (EBC+), indicating that it is in very good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Previous Prices: By looking at the hammer prices of coins with a similar condition (95), we can see that in the past, coins with this condition have reached hammer prices of up to 320 euros (as seen in the auction on 2018-04-25).

3. Starting Price and Average Hammer Price: The current starting price is 150 euros, and the average hammer price for this coin in the past has been 79.06 euros. However, given the high condition, it is likely that the hammer price will be above the average.

4. Market Trends: The coin has been auctioned 139 times, with an 87.8% sell-through rate (122 times sold). This suggests that there is consistent interest in this coin, which may influence a higher hammer price.

5. Estimated Prices in Recent Auctions: In recent auctions, hammer prices of up to 500 euros have been estimated for coins of similar condition.

Taking all these factors into account, an estimated maximum purchase price for this coin could be around 300-350 euros, as this price reflects its high condition and market interest.