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. Previous Prices: By observing previous auction prices for coins with similar conditions (70 and 75), we can see that:
- In past auctions, coins with a condition of 70 have reached hammer prices ranging from 41 to 95 euros.
- Coins with a condition of 75 have reached hammer prices of up to 161 euros.

3. Average Hammer Price: The average hammer price for this coin is 113.17 euros, indicating that, in general, buyers are willing to pay more than the starting price.

4. Recent Trends: In the most recent auctions, the hammer price has been in a range of 130 to 170 euros for conditions of 75 and 80, suggesting an upward trend in prices.

5. Starting Price: The starting price is 30 euros, which is relatively low compared to previous hammer prices.

Based on these factors, an estimated maximum purchase price for the coin with a condition of 70 could be in the range of 90 to 120 euros. This is because, although the condition is not the highest, the interest in the coin and previous hammer prices suggest it could reach a higher price than average.

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