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

1. Current Condition: The coin has a condition rating of 80 (MS+), indicating that it is in relatively good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Current Starting Price and Previous Prices: The current starting price is 120 euros. In previous auctions, we have seen hammer prices that varied significantly, but there are examples of hammer prices exceeding 200 euros for coins with similar or better conditions.

3. Average Hammer Price: The average hammer price for this coin is 155.35 euros, suggesting that, in general, buyers are willing to pay more than the starting price.

4. Historical Trends: Looking at previous hammer prices, there are several instances where coins with conditions of 80 or higher have reached hammer prices of 200 euros or more. For example, in a 2022 auction, a coin with a condition of 80 was sold for 200 euros.

5. Demand and Supply: Since there are no scheduled auctions in the coming days for this coin, demand could be high, which might push the price up.

Based on these factors, an estimated maximum purchase price could be between 200 and 250 euros, considering that the condition is good and there are precedents for hammer prices in that range. However, since the starting price is 120 euros, it is likely that the final hammer price will be closer to the upper end of this range, especially if there is interest among collectors.