To estimate a maximum purchase price for the coin in question, we can analyze the provided data, especially the auction hammer prices from previous sales and the current condition of the coin.

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. Previous Hammer Prices: By looking at the hammer prices of coins with a similar condition (70-80), we can see that:
- In 2020, a coin with a condition of 70 was sold for 200 euros.
- In 2021, another coin with a condition of 80 was sold for 320 euros.
- In 2022, a coin with a condition of 70 was sold for 320 euros.

3. Average Hammer Price: The average hammer price for this coin is 392.45 euros, indicating that, in general, coins of this reference tend to reach higher prices.

4. Starting Price: The current starting price is 90 euros, suggesting that there is considerable room for the hammer price to be higher.

5. Auction Trends: Given that the coin has been auctioned 50 times and has had a high sales percentage (46 out of 50), this indicates a consistent interest in this coin.

Based on these factors, an estimated maximum purchase price for the coin with a condition of 70 could be between 250 and 350 euros, considering that the highest hammer price in the past for coins of similar condition has been 320 euros and that the average hammer price is 392.45 euros.

Therefore, a reasonable maximum purchase price could be 350 euros.