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

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

2. Previous Auction Prices: By looking at previous auction prices for coins with a similar condition (95), we can see that they have reached auction prices of up to 440 euros in recent auctions.

3. Price Trends: The average auction price for coins of similar condition has been approximately 400 euros in recent auctions.

4. Current Starting Price: The starting price of 350 euros is a good indicator, but since the auction price can be significantly higher, it is reasonable to consider a higher auction price.

5. Supply and Demand: Given that there are 3 auctions scheduled in the coming days, this may increase competition and, therefore, the auction price.

Based on these factors, an estimated maximum purchase price for this coin could be between 450 and 500 euros, considering that collector interest and the quality of the coin may lead to competitive bidding.