Based on the data provided, we can observe that the coin in question has had an average auction price of 990.13 euros in previous auctions. Additionally, its current condition is 80 (VF+).

Considering that the average auction price has been 990.13 euros and that the current condition is quite good (80), we could estimate a maximum purchase price slightly higher than this value. Given that the coin will be auctioned in the coming days with a starting price of 1400 euros, and considering that in previous auctions it has reached prices above 1000 euros, we could consider a maximum purchase price around 1200-1300 euros.

It is important to note that the final auction price will depend on the demand at that specific moment, so it is advisable to monitor its evolution to adjust the offer accordingly.