Based on the provided data, we can observe that the coin has had a starting price in the current auction of 18 euros and is in a conservation grade of 70 (MBC-). Additionally, it has been auctioned in the past 28 times, out of which it has been sold 25 times.

The average starting price in previous auctions has been 59.93 euros, while the average final price has been 107.8 euros. Regarding the previous prices of this coin, we can see that it has had significant variations over time, with final prices ranging between 25 euros and 380 euros.

Considering this data, as well as the trend of previous prices and the fact that the coin is in a conservation grade of 70 (MBC-), we could estimate a maximum purchase price around 120-130 euros. This is because the average final price has been 107.8 euros, and considering the conservation grade of the coin, it is reasonable to expect that the final price in this instance could slightly exceed that value.

It is important to note that the final auction price can vary depending on various factors, such as demand at that specific moment, the presence of other interested collectors, among others. Therefore, it is advisable to pay attention to the auction and adjust the offer accordingly.