Based on the provided data, we can observe that the coin in question had a starting price in the most recent auction of 30 euros, with an estimated price of 40 euros and a final price of 40 euros. Additionally, its condition has been described as 100 (UNC).

Considering the previous prices of this coin in past auctions, as well as its evolution, we can see that it has had a fairly variable price range, from 1 euro to 240 euros. However, in the most recent auctions, the final price has been around 40 euros.

Given that the starting price in the most recent auction was 30 euros and the final price was 40 euros, we could estimate a maximum purchase price around 45-50 euros, considering the upward trend in final prices and the fact that the coin is in high condition (100 UNC).

Therefore, an estimated maximum purchase price for this coin in the next auction could be around 45-50 euros.