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 (MS-). This indicates that it is in relatively good shape, but it is not among the highest quality.

2. Historical Prices: By looking at previous auction prices for coins with similar conditions, we can see that:
- In past auctions, coins with conditions of 70 have reached hammer prices that varied, but generally, the hammer prices for similar conditions have been in the range of 30 to 80 euros.
- The last auction of a coin with a condition of 70 had a hammer price of 30 euros.

3. Average Hammer Price: The average hammer price for this coin is 245.58 euros, but this includes coins of better condition. Therefore, it is not a good indicator for our estimation.

4. Recent Trends: In the most recent auctions, hammer prices for coins with similar conditions have been in the range of 30 to 80 euros, suggesting that interest in coins in this state may be stabilizing.

5. Starting Price: The starting price is 15 euros, indicating that the seller has moderate expectations.

Based on these factors, an estimated maximum purchase price for this coin, considering its condition and historical hammer prices, could be in the range of 60 to 80 euros. This reflects a reasonable interest in the coin, given its condition and the market context.