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.

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

1. Current Condition: The coin has a condition rating of 75 (MBC), indicating that it is in acceptable shape, but not in the best condition.

2. Auction History:
- The average starting price in previous auctions is 937.46 euros, and the average hammer price is 1220.84 euros.
- In the past, hammer prices have varied significantly, ranging from 240 euros to 4019.51 euros, depending on the condition and demand at that time.

3. Price Trends:
- The last auction with a similar condition (75) had a hammer price of 276.35 euros, which may be a good indicator of the current market value.

4. Current Starting Price: The starting price is 640 euros, suggesting that the seller has expectations of a higher price, but it may also indicate that the market is not willing to pay that much.

Based on these factors, an estimated maximum purchase price could be positioned within a range between the average hammer price for similar conditions and the current starting price.

Given that the average hammer price for condition 75 has been approximately 276.35 euros in the last auction, and considering that the starting price is 640 euros, a reasonable maximum purchase price could be:

Estimated maximum purchase price: 800 - 1000 euros.

This range allows for a competitive offer without exceeding the historical value of the coin in similar conditions.