Based on the data provided, we can observe that the coin in question has performed well in previous auctions, with final prices significantly exceeding the starting prices. The conservation grade of the coin is at a level of 80 (VF+), which is positive but does not reach the highest level of conservation.

The average starting price in previous auctions has been 69.5 euros, while the average final price has been 285.67 euros. This indicates a considerable interest in this coin among collectors.

Considering the upcoming auction of the coin and taking into account its price history, conservation, and demand, an estimated maximum purchase price could be around 300-350 euros. It is important to note that the final price will depend on various factors, such as competition in the auction and the interest of potential buyers at that specific moment.