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 of the highest quality.

2. Historical Prices:
- The average hammer price for similar coins has been 170.42 euros.
- In previous auctions, hammer prices have varied significantly, with a maximum price of 750 euros in a 2016 auction, although that coin may have had a higher condition.

3. Starting Price and Average Starting Price:
- The current starting price is 60 euros, which is below the average starting price of 102.78 euros. This suggests that there is potential for the hammer price to be higher.

4. Sales Trends: The coin has been sold in 26 out of the last 27 auctions, indicating good demand.

5. Previous Estimates: In recent auctions, the estimated price has been up to 150 euros, and the hammer price has reached up to 140 euros in a recent auction.

Based on these factors, an estimated maximum purchase price could be in the range of 120 to 180 euros. This is because, although the condition is not the best, demand and historical prices suggest that it could reach a higher price at auction.

Therefore, a reasonable maximum purchase price could be 150 euros.