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

1. Current Condition: The coin has a condition of 85 (MS+/EF-), which indicates that it is in relatively good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Historical Prices: By looking at previous auction prices for coins with similar conditions, we can see that the hammer price has varied. For example:
- In 2020, a coin with a condition of 95 was auctioned for 190 euros.
- In 2019, a coin with a condition of 85 was auctioned for 140 euros.
- In 2023, a coin with a condition of 80 was auctioned for 225 euros.

3. Starting Price and Average Hammer Price: The current starting price is 175 euros, and the average hammer price in the past has been 153.41 euros. This suggests that the starting price is reasonable, but it also indicates that the hammer price may be lower than the starting price.

4. Recent Trends: In the most recent auctions, hammer prices have shown a trend of being higher, especially for coins in good condition. For example, in 2023, the hammer price for a similar coin was 182 euros.

Based on these factors, an estimated maximum purchase price could be between 200 and 225 euros, considering that the coin's condition is good and there is interest in quality coins in the current market. This also takes into account the possibility that the hammer price may exceed the starting price, given the interest in well-preserved coins.