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-). This indicates that it is in an acceptable state, but not of high quality.

2. Historical Prices: By looking at the hammer prices of coins with a similar condition (70), we can see that they have varied. For example:
- In previous auctions, coins with a condition of 70 have had hammer prices ranging from 20 to 55 euros.
- The average hammer price for coins with a condition of 70 seems to be around 30-40 euros.

3. Starting Price and Average Hammer Price: The current starting price is 15 euros, and the average hammer price for this coin in the past has been 153.86 euros, but this includes coins in better condition.

4. Recent Trends: In the most recent auctions, hammer prices for coins with a condition of 70 have been in the range of 25 to 55 euros.

Based on this data, an estimated maximum purchase price for this coin, considering its condition and historical prices, could be in the range of 40 to 55 euros. This reflects a price that is reasonable given its state and market trends.