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

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 in the past is 532.61 euros.
- The last auction of this coin with a similar condition (80) had a hammer price of 190 euros, but there are also examples of higher hammer prices, such as 850 euros in a previous auction with a condition of 90.

3. Starting Price and Average Starting Price:
- The current starting price is 200 euros, which is below the average starting price of 273.33 euros. This suggests that there may be room for the hammer price to be higher.

4. Price Trends:
- Looking at previous hammer prices, there is a trend where coins with similar conditions have reached hammer prices that vary significantly, from 170 euros to 850 euros.

5. Data-Based Estimation:
- Given that the average hammer price is 532.61 euros and considering that the current condition is 80, an estimated maximum purchase price could be in the range of 400 to 600 euros, taking into account that the condition is not the highest but still quite good.

Conclusion: An estimated maximum purchase price for this coin could be approximately 600 euros. This price reflects a balance between the current condition, the price history, and the trends observed in previous auctions.