Based on the provided data, the coin in question has a conservation grade of 30 (BC+), with a starting price in the current auction of 18 euros. In the past, this coin has been auctioned twice, both times it was sold, with an average auction price of 67.5 euros.

Additionally, there is information about a previous auction held on October 18, 2017, where the coin was auctioned with a starting price of 18 euros, an estimated price of 30 euros, and it was auctioned off at 35 euros.

Taking into account these data, and considering that the coin is in an acceptable conservation state, with a history of successful auctions and an average auction price of 67.5 euros, we could estimate a maximum purchase price around 70-75 euros for this coin in the current auction.