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. Previous Auction Prices: By observing previous hammer prices for coins with a similar condition (70), the most recent hammer price was 1000 euros in 2020. However, there are other hammer prices that exceed 1000 euros, such as 1110 euros in 2020 and 1400 euros in 2023 for coins with higher conditions.

3. Starting Price and Average Hammer Price: The current starting price is 1100 euros, and the average hammer price in previous auctions is 1415.54 euros. This suggests that the hammer price could be in a similar or higher range than the starting price.

4. Market Trends: The general trend seems to be that hammer prices have been increasing, especially for coins with higher conditions. However, given that the condition of this coin is 70, it is reasonable to expect that the hammer price will not significantly exceed the average hammer price.

5. Estimated Price Analysis: Estimated prices in previous auctions for coins with similar conditions have varied, but many have been in the range of 1400 to 1500 euros.

Based on these factors, an estimated maximum purchase price for this coin could be around 1300-1400 euros. This is based on the starting price, the current condition, and previous hammer prices. However, it is important to keep in mind that the final price may vary depending on competition in the auction and the interest of collectors.