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

2. Historical Prices: By looking at previous auction prices for coins with similar conditions, we can see that:
- In past auctions, coins with a condition of 70 have reached hammer prices of up to 90 euros.
- Coins with a condition of 75 have had hammer prices ranging from 55 to 95 euros.
- Coins with a condition of 80 have reached hammer prices of up to 340 euros, but this is for coins in better condition.

3. Average Hammer Price: The average hammer price for this coin is 114.22 euros, indicating that, in general, buyers are willing to pay more than the starting price.

4. Starting Price: The starting price is 50 euros, which may attract more bidders, but it can also indicate that the seller expects a lower price initially.

5. Auction Trends: The coin has been auctioned 30 times, of which 23 have sold. This suggests that there is consistent interest in the coin, which may increase its value at auction.

Based on these factors, an estimated maximum purchase price for this coin could be between 90 and 120 euros, considering that the condition is a limiting factor and that interest in the coin appears to be solid. Therefore, a reasonable maximum purchase price could be 100 euros.