Based on the data provided, we can observe that the coin in question has performed well in previous auctions, with final prices that have significantly exceeded the starting prices. Additionally, the condition of the coin is at an acceptable level (75 - VF).\n\nThe average starting price in previous auctions has been 81.81 euros, while the average final price has been 286.36 euros. Considering that the starting price for the next auction is 50 euros and the coin has sold in all previous auctions, we could estimate a maximum purchase price around the average final price, approximately 286 euros.\n\nHowever, it's important to note that the highest recorded final price was 700 euros in a recent auction, so there is a possibility that the final price could exceed this estimate. Given the coin's good but not excellent condition, and considering the upward trend in final prices, a prudent estimated maximum purchase price could be around 350-400 euros.