To estimate a maximum purchase price for the coin in question, let's consider several factors:

1. Starting Price: 180 euros. This is the initial price set for the auction.
2. Condition: The coin has a condition rating of 70 (VF-), indicating that it is in fairly good shape, but not of the highest quality (UNC).
3. Auction History: The coin has been auctioned 2 times in the past and has sold on both occasions. This suggests that there is interest in the coin.
4. Previous Prices: In the 2016 auction, the starting price was 40 euros, with a final price of 65 euros. This indicates that the value of the coin has increased over time.
5. Average Final Price: 122.5 euros, which is a good indicator of the current market value.

Given that the current starting price is significantly higher than previous prices, and considering the condition of the coin, an estimated maximum purchase price could be set between the average final price and a bit more, given the interest in the coin.

Therefore, an estimated maximum purchase price could be around 150-160 euros. This reflects a reasonable value considering the condition and auction history, without reaching the starting price, which may be too high for a buyer.