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

1. Current 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. Starting Price: The starting price is 300 euros. This is an indicator of the seller's expectation regarding the coin's value.

3. Sales History: By looking at previous auction prices for coins with similar conditions (95 and 90), we can see that they have reached hammer prices that vary considerably. For example, in past auctions, coins with a condition of 95 have reached hammer prices of up to 700 euros.

4. Recent Trends: In the most recent auctions, the hammer price for coins of similar condition has been quite high, suggesting that there is growing demand.

5. Average Hammer Price: The average hammer price for this coin is 135.49 euros, but given that the condition is higher, we can expect the actual hammer price to be significantly higher.

Based on these factors, an estimated maximum purchase price could be between 500 and 700 euros, considering that the condition is high and there is a history of hammer prices that supports this estimate. However, since the starting price is 300 euros, it is likely that the actual hammer price will be closer to this upper range, depending on the competition in the auction.