Based on the provided data, we can see that the coin in question has a grade of 30 (BC+), with a starting price in the current auction of 25 euros. Additionally, it has been auctioned in the past three times, with an average starting price of 60 euros and an average closing price of 85.67 euros.

Two specific prices from previous auctions are also given:

1. In the auction on May 27, 2014, the coin had a starting price of 125 euros, an estimated price of 250 euros, and closed at 130 euros.
2. In the same auction on May 27, 2014, the coin had a starting price of 30 euros, an estimated price of 50 euros, and closed at 35 euros.

Since the coin has sold in all previous auctions, we can assume there is demand among collectors. Considering the grade of 30 (BC+), the current starting price of 25 euros, and the prices from past auctions, we could estimate a maximum purchase price of around 100-120 euros. This estimation is based on the fact that the average closing price in past auctions was 85.67 euros and considering the coin's history of selling in all previous instances.

Therefore, an estimated maximum purchase price for this coin in the current auction could be around 100-120 euros.