Based on the data provided, we can observe that the coin in question has had an average auction closing price of 43.63 euros in previous auctions. Additionally, its current condition is graded at 95 (EBC+).

Considering that the coin will be auctioned in the upcoming days with a starting price of 50 euros, we can estimate a maximum purchase price based on the historical average auction closing price and the current condition. Given the high condition grade and the average auction closing price of 43.63 euros, we could consider a maximum purchase price around 50-55 euros.

It is important to note that the final auction price may vary depending on the demand at that specific moment, so it is advisable to monitor the auction to adjust the offer accordingly.