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

1. Condition of the coin: The coin has a condition rating of 95 (EBC+), which indicates that it is in very good condition. This generally translates to a higher price compared to coins with lower condition ratings.

2. Auction history: By observing previous hammer prices of coins with a similar condition (95), we can see that in the past, coins of this type have reached hammer prices of up to 700 euros (as seen in the auction on October 19, 2022).

3. Starting price and average prices: The current starting price is 450 euros, and the average hammer price in previous auctions is 94.76 euros, suggesting that the current starting price is significantly higher than the average hammer price. However, this may indicate that the coin is valued more for its condition or rarity.

4. Sales trends: The coin has sold in 74 out of 89 auctions, indicating good demand. Additionally, the fact that it will be auctioned in the coming days may increase interest and price.

Based on these factors, an estimated maximum purchase price could be in the range of 600 to 800 euros, considering that the highest hammer price in the past was 700 euros and that the coin's condition is high. This also takes into account the possibility that interest in the current auction could drive the price beyond what has been seen previously.