Based on the data provided, we can observe that the coin in question has had an average auction closing price of 101.73 euros in previous auctions. Additionally, its condition has been maintained at an average of 70 (VF+).

Considering that the starting price for the next auction is 30 euros and that the historical average closing price has been 101.73 euros, we could estimate a maximum purchase price around that value. However, taking into account the coin's condition of 70 (VF+), we could adjust that price downwards.

Given that the coin has been sold in the past in a price range between 35 and 100 euros, and considering its condition and the current starting price, we could estimate a maximum purchase price around 90-95 euros. This would take into account both the price history and the condition of the coin.

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 pay attention to the auction and adjust the offer accordingly.