Based on the provided data, we can see that the coin in question has had starting prices ranging from 5 euros to 500 euros in previous auctions. The average starting price of past auctions is 85.96 euros, while the average final price is 69.28 euros.

The condition of the coin to be auctioned is described as 70 (MBC-), meaning it is in fairly acceptable condition but not in perfect condition.

Given that the coin has sold in the past for prices ranging from 10 euros to 110 euros, and considering its current condition as well as the fact that it has been auctioned 27 times before, we could estimate a maximum purchase price around 90-100 euros. This takes into account that the average final price has been 69.28 euros and that the coin has reached higher prices in previous auctions.

It is important to note that the final auction price will depend on the demand at that specific moment, so it is advisable to pay attention to the auction to adjust the offer accordingly.