To estimate a maximum purchase price for the coin that will be auctioned, we can consider several factors:

1. Coin Condition: The coin in question has a condition of 95 (S/C-), which indicates that it is in very good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Previous Auction Prices: By observing the hammer prices of coins with a similar condition (95), we can see that they have reached hammer prices of up to 900 euros in previous auctions. For example:
- In 2020, a coin with a condition of 95 was auctioned and reached a hammer price of 600 euros.
- In 2019, another coin with the same condition was also sold for 600 euros.

3. Average Hammer Price: The average hammer price for this coin is 436.04 euros, which provides an additional reference point.

4. Starting Price: The starting price of 450 euros is a good indicator of what is expected to be obtained in the auction.

Given that the condition is high and considering the previous hammer prices, an estimated maximum purchase price could be in the range of 600 to 900 euros. However, since the starting price is 450 euros, a reasonable maximum bid price could be approximately 700 euros. This allows for competition in the auction without exceeding the historical hammer prices for coins of similar condition.