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

1. Starting price: 460 euros.
2. Current condition: 85 (ebc-), which indicates good condition, although not the best.
3. Auction history: The coin has been auctioned 2 times in the past, and both times it sold. The average hammer price in the past was 480 euros.
4. Estimated price in the previous auction: In the December 2021 auction, the estimated price was 500 euros, but the hammer price was 460 euros, indicating that the market may have adjusted its value.

Given that the current condition is lower than that of the previous auction (90), and considering that the average hammer price is 480 euros, a reasonable maximum purchase price could be in the range of 480 to 500 euros, but since condition is an important factor, it is wise not to exceed the average hammer price.

Therefore, an estimated maximum purchase price could be 480 euros. This reflects the current market value and the condition of the coin.