Based on the data provided, we can observe that the coin in question had a starting price of 18 euros in this auction and is in a conservation grade of 30 (BC+). Additionally, it has been auctioned in the past five times, with an average starting price of 45.75 euros and an average closing price of 82.4 euros.

When analyzing the previous prices of this coin, we can see that in the last recorded auction in November 2021, the coin was sold for 70 euros with a conservation grade of 75. In previous auctions, closing prices have varied, reaching as high as 115 euros on one occasion.

Taking into account this data and the history of closing prices, as well as the current conservation grade of the coin, we could estimate a maximum purchase price around 90-100 euros. It is important to consider that the final price will depend on the demand at the auction and the willingness of participants to bid on this particular coin.