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+), indicating that it is in quite 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 200 euros, and the average hammer price in previous auctions is 258.72 euros. This suggests that the hammer price tends to be higher than the starting price.

3. Sales History: The coin has been auctioned 47 times, of which 44 have been successful sales. This indicates good demand and consistent interest in the coin.

4. Previous Hammer Prices: Looking at previous hammer prices for coins with similar conditions (80), we can see that they have reached hammer prices of up to 650 euros in recent auctions. However, most hammer prices for condition 80 seem to be in the range of 220 to 400 euros.

5. Recent Trends: The most recent hammer prices (2023) have been quite high, which could indicate an increase in demand or in the coin's value.

Based on these factors, an estimated maximum purchase price could be in the range of 350 to 450 euros, considering that the coin is in good condition and that recent hammer prices have been high. Therefore, a reasonable maximum purchase price could be 400 euros.