To estimate a maximum purchase price for the coin in question, we can consider several factors based on the provided data:

1. Current Condition: The coin has a condition rating of 70 (VF-). This indicates that it is in an acceptable state, but not among the best qualities.

2. Auction History:
- The average hammer price for similar coins in the past is 2367.7 euros.
- The average starting price is 805.24 euros.
- The coin has been auctioned 34 times, of which it has sold 24 times, indicating good demand.

3. Previous Prices:
- In previous auctions, hammer prices have varied significantly, ranging from 90 euros to over 27,000 euros, depending on the condition and demand at that time.
- The last auction with a similar condition (70) had a hammer price of 106 euros.

4. Price Trends:
- Hammer prices tend to be higher for coins in better condition. A condition rating of 70 suggests that the hammer price could be below the overall average, but it could still be significant.

5. Estimation:
- Given that the starting price is 250 euros and considering the hammer price history and condition, a reasonable maximum purchase price could be in the range of 600 to 800 euros. This is based on the fact that buyers are often willing to pay a little more than the starting price, especially if there is interest in the coin.

Therefore, an estimated maximum purchase price for this coin could be approximately 700 euros.