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

1. Condition of the coin: 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 auction prices: By observing the hammer prices of similar coins in the past, we can see significant variations depending on the condition. For example, in previous auctions, coins with similar conditions have reached hammer prices ranging from 60 to 547 euros.

3. Starting price and average hammer price: The current starting price is 200 euros, and the average hammer price for similar coins is 81.91 euros. However, since the condition of this coin is above average, it is reasonable to expect that the hammer price will be higher.

4. Auction trends: The coin has been auctioned 139 times, with an 80% sell-through rate, indicating a consistent interest in this coin. This may influence demand and, therefore, the price.

5. Previous estimated prices: In past auctions, the estimated price for coins with similar conditions has been up to 450 euros, suggesting that there is significant potential for a higher hammer price.

Taking all these factors into account, an estimated maximum purchase price for this coin could be around 350-400 euros. This reflects both the high condition of the coin and the demonstrated interest in previous auctions.