Based on the data provided, we can observe that the coin in question has had an average starting price of 41.71 euros in previous auctions, with an average closing price of 53.76 euros. The condition of this coin is described as '25 (BC)'.

Additionally, several previous prices of this coin have been recorded in past auctions, with price estimates ranging between 40 and 110 euros, depending on the auction date and the condition of the coin.

Given that the coin will be auctioned in euros and considering its price history, condition, and past demand, an estimated maximum purchase price for this coin could be around 100 euros. It is important to note that this is just an estimate and the final price at auction may vary depending on various factors, such as competition from other bidders and interest in the coin at that specific time.