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-). This is an important factor, as coins in better condition tend to reach higher prices.

2. Auction History:
- The average hammer price for similar coins in the past is 84.07 euros.
- Previous auctions of this coin have shown hammer prices that vary, but there are examples of sales reaching up to 300 euros for coins in better condition (condition rating of 95).

3. Price Trends:
- In recent auctions, hammer prices for coins with similar condition (70) have been in the range of 50 to 100 euros, with some cases reaching up to 130 euros.

4. Starting Price and Average Starting Price:
- The starting price is 35 euros, and the average starting price is 40 euros. This suggests that the hammer price could be significantly higher than the starting price.

5. Estimation Based on Historical Data:
- Given that the average hammer price is 84.07 euros and considering that the condition of this coin is 70, an estimated maximum purchase price could be positioned in a range above the average, but not as high as the prices for higher condition ratings.

Based on these factors, an estimated maximum purchase price for this coin could be approximately 100 euros. This is based on the historical hammer price data for coins of similar condition and the potential for collector interest to drive the price up at auction.