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

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

2. Auction History:
- The average hammer price for this coin in the past is 277.78 euros.
- Previous hammer prices have varied, with a maximum of 700 euros in a recent auction (2022) and a minimum of 84 euros.
- Most of the time, the coin has sold for above its starting price, indicating consistent demand.

3. Current Starting Price: The starting price is 200 euros, which is slightly higher than the average starting price of 107.22 euros, but this can be justified by the coin's condition.

4. Price Trends: Looking at previous hammer prices, it seems that coins in similar conditions have reached hammer prices ranging from 230 to 700 euros, depending on the condition and demand at the time of the auction.

5. Estimation: Given that the coin's condition is rated at 85 and considering the price history, an estimated maximum purchase price could be in the range of 300 to 400 euros. This is based on the fact that the coin has reached hammer prices above 300 euros on several occasions and that the current condition is favorable.

Therefore, an estimated maximum purchase price for this coin could be 350 euros.