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

1. Current Condition: The coin has a condition rating of 80 (MBC+). This is an important factor, as coins in better condition tend to reach higher prices.

2. Auction History:
- The average hammer price for this coin is 228.35 euros.
- In the past, hammer prices have varied based on condition. For example, a coin with a condition of 95 was sold for 300 euros, while one with a condition of 70 sold for 220 euros.

3. Starting Price: The current starting price is 180 euros, which is below the average hammer price.

4. Price Trends: By observing the hammer prices of coins with similar conditions (70-85), it can be seen that hammer prices have ranged from 150 to 360 euros.

Given that the coin's condition is 80, which is in an intermediate range, and considering the auction price history, an estimated maximum purchase price could be around 250-300 euros. This is based on the fact that the average hammer price is 228.35 euros and that coins with similar conditions have reached higher prices.

Therefore, an estimated maximum purchase price for this coin could be approximately 280 euros.