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 of 70 (MBC-). This is an important factor, as coins in better condition tend to reach higher prices.

2. Starting Price and Average Hammer Price: The starting price is 50 euros, and the average hammer price in previous auctions is 73.25 euros. This suggests that, in general, coins of this reference tend to sell for above their starting price.

3. Sales History: The coin has been auctioned 119 times, of which it has sold 105 times. This indicates good demand and a history of successful sales.

4. Previous Prices: Looking at previous hammer prices for coins with a similar condition (70), the highest recorded price was 100 euros, while other hammer prices in the condition range of 70 have been between 50 and 75 euros.

5. Recent Trends: In the most recent auctions, hammer prices for coins with similar conditions have shown a range of 60 to 110 euros.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 90 to 110 euros, considering that the condition is good and there is a history of hammer prices that supports this estimate.

Therefore, a reasonable maximum purchase price could be 100 euros.