Based on the provided data, we can observe that the coin in question has had a starting price in the current auction of 45 euros and is in a conservation grade of 70 (MBC-). Additionally, it has been auctioned in the past on several occasions, with closing prices ranging between 15 and 1400 euros.

The average closing price of this coin in previous auctions has been 265.09 euros, while the average starting price has been 183.28 euros. Considering the current conservation grade of 70 (MBC-), we can estimate that the closing price of this coin in the current auction could be around 265 euros.

Given that the starting price is 45 euros and considering the upward trend of previous closing prices, as well as the conservation of the coin, we could estimate a maximum purchase price in this auction of around 300 euros. It is important to note that this is just an estimate and the final price could vary depending on demand and other factors in the auction.