Based on the data provided, we can observe that the coin in question has had an average auction closing price of 145.9 euros in previous auctions. Additionally, its current condition is 70 (VF-).

Considering that the starting price for the next auction is 100 euros and the historical average closing price is 145.9 euros, we can estimate a maximum purchase price around that range. Given that the condition of the coin is 70 (VF-), we could consider an estimated maximum purchase price between 140 and 150 euros.

It is important to note that the final auction price may vary depending on factors such as demand at that specific time, competition from other bidders, and interest in the particular coin.