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 85 (MS+/EF-), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Current Listing Price and Previous Prices: The current listing price is 1570 euros. In previous auctions, hammer prices for coins with a similar condition have varied, but there are recent examples where coins with a condition of 85 have reached hammer prices of up to 1700 euros.

3. Price Trends: By observing the hammer prices from previous auctions, it can be noted that the average hammer price has been 1365.75 euros, but there are also examples where higher prices have been achieved, especially in recent auctions.

4. Market Expectations: Given that there are no auctions scheduled in the coming days and considering that the coin has been auctioned 67 times in the past, there is a consistent interest in this reference.

Based on these factors, an estimated maximum purchase price could be around 1700-1800 euros, considering that interest in coins in good condition tends to increase and that the hammer price can exceed the listing price in competitive auctions.