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

1. Starting Price: 90 euros.
2. Condition: The coin has a condition of 85 (ebc-), indicating that it is in quite good shape.
3. Auction History:
- In 2019, a coin with a condition of 70 sold for 30 euros.
- In 2014, a coin sold for 25 euros with a starting price of 15 euros.
- In 2014, another coin sold for 460 euros with a starting price of 200 euros, although the condition is not specified.
- In 2022, a coin with a condition of 85 sold for 300 euros with a starting price of 90 euros.

4. Average Hammer Price: 207 euros, indicating that, in general, coins of this reference tend to sell for higher prices than the starting price.

Given that the condition of the coin in the current auction is 85, similar to the 2022 auction that reached a hammer price of 300 euros, and considering that the average hammer price is 207 euros, we can estimate that the maximum purchase price could be in a higher range.

Taking all these factors into account, an estimated maximum purchase price could be around 250-300 euros. This is based on the performance of coins with similar conditions and the auction price history.