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-), which indicates that it is in relatively good shape, but not the best possible condition.

2. Auction History:
- The average hammer price for coins of similar condition (70) has been approximately 30-70 euros in previous auctions.
- In past auctions, hammer prices have varied, but there are examples of sales at 30, 35, and even 70 euros for coins with the same condition.

3. Starting Price and Previous Prices:
- The current starting price is 25 euros, which is reasonable given the history of starting and hammer prices.
- The average hammer price in the past has been 50.17 euros, suggesting there is potential for a higher sale price.

4. Recent Trends:
- In the most recent auctions, hammer prices have been 65 euros and 45 euros for coins with conditions of 80, indicating a growing interest in coins of good condition.

Based on these factors, an estimated maximum purchase price for the coin could be between 60 and 80 euros, considering that the condition is good and there is a history of hammer prices that supports this estimate.

Therefore, a reasonable maximum purchase price could be 70 euros.