Based on the data provided, we can observe that the coin in question has had a starting price in previous auctions ranging between 9 and 55 euros, with an estimated price ranging between 15 and 70 euros. The average starting price of previous auctions has been 22.47 euros, while the average final price has been 20.45 euros.

The conservation grade of the coin to be auctioned is 75 (VF), indicating that it is in an acceptable but not excellent condition.

Given that the coin has been auctioned 15 times in the past, with a total of 11 sales and 4 times it did not sell, we can infer that there is market interest in this coin.

Taking all these factors into consideration, and considering that the coin will be auctioned in euros, a maximum estimated purchase price for this coin in the next auction could be around 40-50 euros. It is important to note that the final price will depend on the demand at the time of the auction and the competition from other potential buyers interested in the coin.