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

1. Current Condition: The coin has a condition rating of 70 (VF-). This indicates that it is in an acceptable state, but not of high quality. In the coin market, condition is a key factor that influences price.

2. Auction History:
- The average hammer price for similar coins in the past is 99.29 euros.
- The coin has been auctioned 26 times, of which it has sold 24 times, indicating good demand.
- Previous hammer prices for coins with similar conditions (70) have varied, but there are examples of auctions reaching up to 120 euros.

3. Starting Price and Average Starting Price:
- The current starting price is 25 euros, which is relatively low compared to the average hammer price.
- The average starting price of 57.42 euros also suggests that there is room for the hammer price to be significantly higher.

4. Recent Trends: In the most recent auctions, hammer prices for coins with similar conditions have been in the range of 60 to 95 euros.

Based on these factors, an estimated maximum purchase price could be in the range of 90 to 120 euros, considering that the condition is 70 and there is a history of hammer prices that supports this estimate.

Therefore, a reasonable maximum purchase price could be 100 euros.