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

1. Current Condition: The coin has a condition of 80 (MBC+), which indicates that it is in quite good shape. This is important because coins in better condition tend to reach higher prices.

2. Previous Prices: By looking at previous auction prices for coins with similar conditions (80 and 85), we can see that auction prices have varied. For example:
- In 2020, a coin with a condition of 80 was auctioned for 170 euros.
- In 2023, a coin with a condition of 85 was auctioned for 300 euros.
- In 2022, a coin with a condition of 80 was auctioned for 250 euros.

3. Starting Price and Average Auction Price: The current starting price is 175 euros, and the average auction price for this coin is 152.01 euros. This suggests that the starting price is reasonable, but it also indicates that the auction price may be lower than the starting price.

4. Recent Trends: In the most recent auctions, auction prices have shown an increase, especially for coins in good condition. This may indicate an upward trend in interest for coins of this reference.

5. Estimation Based on Historical Data: Given that the coin has a condition of 80 and considering previous auction prices, an estimated maximum purchase price could be in the range of 200 to 250 euros, based on the fact that similar coins have reached auction prices in that range.

Conclusion: An estimated maximum purchase price for this coin could be approximately 225 euros. This is based on the condition, previous auction prices, and market trends.