To estimate a maximum purchase price for the coin in question, let's consider several factors:

1. Current Condition: The coin has a condition of 75 (MBC), which indicates that it is in quite good shape. This generally increases its value compared to coins with lower conditions.

2. Auction History:
- In the auction on December 16, 2020, the coin was auctioned with a starting price of 200 euros and sold for 200 euros, indicating that there was no increase in price on that occasion.
- In the auction on March 6, 2024, the condition was 70, and there is no information on the final price, but the starting price was 200 euros.

3. Average Hammer Price: The average hammer price for this coin has been 255 euros, suggesting that, in general, buyers are willing to pay more than the starting price.

4. Demand and Supply: Since it will not be auctioned in the coming days and there has been prior interest (2 sales out of 3 auctions), this may indicate that there is a market for this coin.

Based on these factors, an estimated maximum purchase price could be positioned between the average hammer price (255 euros) and a bit more, considering the current condition and interest in the coin.

Therefore, an estimated maximum purchase price could be around 280-300 euros. This takes into account the good condition and price history, but it is also wise not to exceed the average hammer price too much to avoid overpaying.