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 is an important factor, as coins in better condition tend to reach higher prices.

2. Starting Price and Average Hammer Price: The starting price is 1300 euros, and the average hammer price in previous auctions is 1336.65 euros. This suggests that the hammer price is usually close to the starting price.

3. Sales History: The coin has been auctioned 58 times, of which it has sold 54 times. This indicates good demand and a history of successful sales.

4. Previous Prices: By looking at previous hammer prices for coins with similar conditions, we can see that prices have varied. For example, in previous auctions, coins with conditions of 70 have reached hammer prices of up to 1500 euros.

5. Recent Trends: In the most recent auctions, hammer prices have been in the range of 1500 to 2000 euros for coins of similar condition.

Based on these factors, an estimated maximum purchase price for this coin could be between 1500 and 1800 euros, considering that the condition and market demand are favorable. However, since the starting price is 1300 euros, it is likely that the hammer price will not significantly exceed this range. Therefore, a reasonable maximum purchase price could be 1600 euros.