To estimate a maximum purchase price for the coin in question, we can analyze the provided data and consider several factors:

1. Current Condition: The coin has a condition of 70 (VF-), which indicates that it is in relatively good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History: The coin has been auctioned 9 times and has sold on all occasions. This suggests that there is consistent interest in the coin, which may increase its value.

3. Previous Hammer Prices: Previous hammer prices are a good indicator of the coin's value. For example:
- In 2020, a coin with a condition of 30 sold for 240 euros.
- In 2015, several coins with unspecified conditions sold for between 180 and 500 euros.
- In 2017, a coin sold for 500 euros, although the condition is not specified.

4. Average Hammer Price: The average hammer price for this coin is 325.56 euros, which provides a solid benchmark.

5. Starting Price: The starting price is 200 euros, indicating that the seller expects a reasonable minimum price.

Given that the coin's condition is 70 (VF-), which is better than the conditions of some coins that have sold for higher prices, and considering the average hammer price, an estimated maximum purchase price could be positioned above the average hammer price.

Estimated Maximum Purchase Price: Based on the previous analysis, a reasonable maximum purchase price could be between 400 and 500 euros, taking into account the condition and historical interest in the coin. This would allow for competitive bidding in the auction without exceeding the market value observed in previous auctions.