Based on the provided data, we can observe that the coin in question had a starting price of 18 euros in the most recent auction, with a conservation value of 85 (ebc-). Additionally, it has been auctioned 21 times in the past, sold in 16 instances and not sold in 5 instances.

The average starting price of this coin in previous auctions has been 25.95 euros, while the average final price has been 36.43 euros. Regarding the previous prices of this coin, we can see that it has had variations in its starting, estimated, and final prices over the years, with conservation values ranging between 80 and 95.

Given that the coin will be auctioned in the upcoming days with a starting price of 18 euros and considering its previous auction history and current conservation, we could estimate a maximum purchase price around 40-45 euros. It is important to note that this is just an estimate and the final price could vary depending on the demand at the auction.