Based on the provided data, we can observe that the coin has had an average auction closing price of 47.71 euros in previous auctions. Additionally, the current condition of the coin is 70 (VF-).

Considering that the coin's condition is in a medium state, and that the average auction closing price in previous auctions has been 47.71 euros, we could estimate a maximum purchase price around that value or slightly higher, taking into account the upward trend in closing prices.

Therefore, an estimated maximum purchase price for this coin in the next auction could be around 50-55 euros, considering the condition and previous closing prices.