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. Previous Prices: By observing previous auction prices for coins with similar conditions, we can see that:
- In 2020, a coin with a condition of 80 sold for 320 euros.
- In 2021, a coin with a condition of 70 sold for 270 euros.
- In 2022, a coin with a condition of 80 sold for 400 euros.

3. Starting Price and Average Hammer Price: The current starting price is 325 euros, and the average hammer price in the past has been approximately 289.38 euros.

4. Recent Trends: In the most recent auctions, hammer prices have shown a trend of increasing, especially for coins in good condition.

5. Comparison with Estimated Prices: The estimated price for the coin in the current auction is 325 euros, indicating that the auctioneers expect considerable interest.

Taking all these factors into account, an estimated maximum purchase price could be between 350 and 400 euros, considering that the condition of the coin is slightly lower than those that have reached higher prices in the past. This would allow for competitive bidding in the auction without exceeding a reasonable limit based on historical data.