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-), indicating that it is in an acceptable state, but not among the best qualities. This may influence the price, as coins in better condition tend to reach higher prices.

2. Auction History:
- The coin has been auctioned 5 times in the past, of which it has sold 3 times. This indicates that there is interest in the coin, but also that there is a 40% chance it has not sold.
- Previous hammer prices are relevant. For example, in the 2019 auction, the coin sold for 950 euros with a condition of 80, and in 2024 it was hammered at 1100 euros with a condition of 75. This suggests that the price may fluctuate depending on the condition and market interest.

3. Starting Prices and Average Prices:
- The current starting price is 700 euros, which is lower than the average starting price of 840 euros and the average hammer price of 1016.67 euros. This suggests that the starting price is attractive and could attract more bidders.

4. Price Trends:
- The highest recorded hammer price is 1100 euros, which sets an upper limit for the purchase price.

Based on these factors, an estimated maximum purchase price could be between the average hammer price (1016.67 euros) and the highest hammer price (1100 euros). Given that the current condition is 70, which is lower than the conditions of previous auctions, a reasonable maximum price could be approximately 1000 euros. This reflects a balance between market interest, the condition of the coin, and historical prices.