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 relatively good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Starting Price and Average Hammer Price: The starting price is 70 euros, and the average hammer price in previous auctions is 104.74 euros. This suggests that, on average, similar coins have reached prices above the starting price.

3. Sales History: The coin has been auctioned 44 times, of which 39 have resulted in sales. This indicates good demand and consistent interest in the coin.

4. Previous Prices: Looking at previous hammer prices for coins with similar conditions, we can see that they have reached hammer prices that vary, but some have reached 150 euros or more in similar conditions.

5. Recent Trends: In the most recent auctions, the hammer prices have shown a range that suggests the coin could reach a hammer price above average, especially considering the growing interest in coins of good condition.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 120 to 150 euros. This is based on the condition, price history, and recent sales trends.