Based on the data provided, we can observe that the coin in question has had a significant variation in auction closing prices in previous auctions. The starting price for the next auction is 15 euros, and the coin's condition is estimated at 70 (VF+).

Taking into account the previous auction closing prices, the coin's condition, and the fact that it has been auctioned numerous times, we could estimate a maximum purchase price of around 110 euros. This price aligns with the highest closing prices recorded in the past and takes into consideration the coin's condition.

It is important to note that the final auction price may vary depending on factors such as demand at that specific time, the number of interested parties in the coin, and other elements that influence the auction process.