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 rating 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 fetch higher prices.

2. Auction History:
- The average hammer price for similar coins has been 71.94 euros.
- In previous auctions, the hammer price has varied, with a maximum of 120 euros for a coin with a condition of 80 and a minimum of 31 euros for one with a condition of 70.
- The coin has sold in 20 out of 26 auctions, indicating good demand.

3. Starting Price and Estimates:
- The current starting price is 60 euros, which is slightly higher than the average starting price of 41.72 euros.
- The estimated price for this auction is 90 euros, suggesting expectations for it to reach a higher price.

4. Price Trends:
- In recent auctions, hammer prices have shown a tendency to be above the starting price, especially for coins in similar conditions.

Based on these factors, an estimated maximum purchase price could be around 90-100 euros, considering that the estimated price is 90 euros and that in the past, hammer prices have reached up to 120 euros for coins in better condition. However, given that the condition of this coin is 70, a more conservative maximum purchase price could be approximately 90 euros.