To estimate a maximum purchase price for the coin in question, we will consider several factors:

1. Condition: The coin has a condition of 70 (VF-), which indicates that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction history:
- The average hammer price for similar coins has been 48.36 euros.
- In previous auctions, the hammer price has varied, but it has reached up to 115 euros on one occasion (although that coin may have had a different condition).

3. Starting price and estimates:
- The current starting price is 40 euros, which is slightly higher than the average starting price of 36.19 euros.
- The estimated price for this auction is 60 euros, suggesting that there are expectations for the coin to sell for a price above the starting price.

4. Sales trends: Of the 20 times it has been auctioned in the past, it has sold 16 times, indicating good demand.

Based on these factors, an estimated maximum purchase price could be around 60-70 euros, considering that the average hammer price is 48.36 euros and that the estimated price for this auction is 60 euros. However, given the hammer price history and the condition of the coin, a maximum of 70 euros seems reasonable.

Therefore, the estimated maximum purchase price would be 70 euros.