Based on the provided data, we can observe that the coin in question has had an average starting price of 34.83 euros in previous auctions, with an average closing price of 39.86 euros. The current condition of the coin is 70 (VF+).

Considering that the coin has been auctioned 12 times in the past, with 8 successful sales and 4 unsold, and that it will be auctioned once again in the coming days, we can infer that there is interest in this coin among collectors.

Analyzing the previous prices of the coin, we see that it has had variations in starting prices, estimates, and closing prices throughout the auctions. However, the maximum estimated purchase price can be calculated by taking into account the highest price reached in previous auctions.

Given that the highest price reached in a previous auction was 140 euros, and considering the current condition is 70 (VF+), we could estimate a maximum purchase price around 140 euros or slightly higher, depending on the demand in the upcoming auction.

Therefore, an estimated maximum purchase price for this coin in the next auction could be around 140-150 euros, considering its price history and condition.