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 of 70 (VF-). This is an important factor, as coins in better condition tend to reach higher prices.

2. Auction History:
- The coin has been auctioned 8 times, of which it has sold 5 times. This indicates that there is interest in the coin, although there is also a 37.5% chance that it has not sold.
- Previous hammer prices varied, but there are examples of hammer prices reaching up to 1600 euros (in 2016).

3. Average Starting and Hammer Prices:
- The average starting price is 732.64 euros and the average hammer price is 1067.66 euros. This suggests that, in general, coins of this reference tend to sell above the starting price.

4. Previous Prices:
- Previous hammer prices for coins with similar conditions (75 and 90) have reached up to 1482.87 euros. However, the condition of 70 is lower than those examples, suggesting that the hammer price could be lower.

5. Market Trends: Since it will not be auctioned in the coming days, this could increase demand in the future, which could influence the price.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 600 to 800 euros, considering that the condition is not the best and that the starting price is 80 euros. However, given the history of hammer prices, a reasonable maximum purchase price could be approximately 800 euros.