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 generally translates to a higher value compared to coins in lower conditions.

2. Historical Prices: By looking at previous auction prices for coins with similar conditions, we can see that prices have varied considerably. For example:
- In 2016, a coin with a condition of 107 sold for 260 euros.
- In 2019, a coin with a condition of 85 sold for an unspecified price, but it is estimated to be in the range of 80-100 euros.

3. Average Auction Price: The average auction price for this coin is 59.67 euros, which provides a useful benchmark.

4. Recent Trends: In the most recent auctions, hammer prices have ranged from 30 to 110 euros, depending on the condition.

5. Starting Price: The current starting price is 45 euros, suggesting that the seller has moderate expectations.

Based on these factors, an estimated maximum purchase price for this coin, considering its good condition and historical prices, could be between 80 and 100 euros. This aligns with recent price trends and the coin's condition value.

Therefore, an estimated maximum purchase price could be 100 euros.