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

1. Current Condition: The coin has a condition of 85 (ebc-), which indicates that it is in quite good shape. This is important because coins in better condition tend to reach higher prices.

2. Auction History:
- The average hammer price for similar coins has been 1136.93 euros.
- In previous auctions, coins with a similar condition (85) have reached hammer prices of up to 1200 euros.
- The last auction with a condition of 85 had a hammer price of 950 euros.

3. Starting Price and Average Starting Price:
- The current starting price is 600 euros, which is lower than the average starting price of 632.35 euros. This may indicate a good buying opportunity.

4. Price Trends:
- In previous auctions, the hammer price has varied, but generally, coins with a condition of 85 have had a hammer price range between 700 and 1200 euros.

Based on these factors, an estimated maximum purchase price could be around 1100 euros. This price reflects a balance between the condition, the auction price history, and the current starting price. However, it is important to keep in mind that the market can be volatile and that other factors, such as demand at the time of the auction, can also influence the final price.