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 of 70 (VF-). This is an important factor, as coins in better condition tend to fetch higher prices.

2. Starting Price and Average Hammer Price: The starting price is 75 euros, and the average hammer price in previous auctions is 198.08 euros. This suggests that, in general, coins of this reference tend to sell for a significantly higher price than their starting price.

3. Sales History: The coin has been auctioned 41 times, of which 36 have resulted in sales. This indicates good demand and consistent interest in this coin.

4. Previous Prices: Looking at previous hammer prices, there are examples of coins with similar conditions that have sold for prices that vary considerably. For instance, in recent auctions, coins with conditions of 80 and 85 have reached hammer prices of up to 400 euros.

5. Recent Trends: In the most recent auctions, hammer prices have shown a wide range, with some reaching up to 360 euros. This suggests that there is potential for the coin to reach a higher price in the next auction.

Taking all these factors into account, an estimated maximum purchase price for the coin could be in the range of 200 to 250 euros. This is based on the average hammer price and the price trend of coins with similar conditions. However, it is important to consider that collector interest and competition in the auction will also influence the final price.