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

1. Current Condition: The coin has a condition of 70 (VF-), indicating that it is in relatively good shape, but not of the best quality (UNC).

2. Auction History:
- The average hammer price in previous auctions has been 32 euros.
- Previous auctions with similar conditions (75) have had hammer prices ranging between 45 and 67 euros.
- The last auction with a condition of 30 had a hammer price of 40 euros, suggesting that condition significantly influences the price.

3. Starting Price: The current starting price is 25 euros, which is a good starting point.

4. Price Trends: Observing previous hammer prices, it seems there is a trend for coins with similar conditions to sell above the starting price, especially if the condition is better.

Given that the condition of the coin is 70 and considering the hammer price history, an estimated maximum purchase price could be between 40 and 60 euros. This is based on the fact that, although the condition is not the best, there is a price history suggesting it could reach a higher price at auction.

Therefore, a reasonable estimated maximum purchase price could be 50 euros.