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

1. Current Condition: The coin has a condition of 70 (MS-). This indicates that it is in an acceptable state, but not of high quality.

2. Previous Auction Prices: By observing the auction prices of coins with similar conditions (around 70), we can see that the auction prices have varied. For example:
- In previous auctions, coins with a condition of 70 have reached auction prices between 100 and 150 euros.
- The average auction price for coins with similar conditions seems to be around 130-140 euros.

3. Starting Price and Average Auction Price: The current starting price is 125 euros, and the average auction price for this coin in the past has been 146.93 euros. This suggests that the auction price could be in a similar range or slightly above the starting price.

4. Recent Trends: In the most recent auctions, the auction prices for coins with similar conditions have shown a slight increase, which could indicate a rising trend in interest for these coins.

Based on these factors, an estimated maximum purchase price for this coin could be between 150 and 180 euros. This is because, although the condition is not the best, the market interest and previous auction prices suggest that it could reach a higher price than the starting price.

Therefore, a reasonable maximum purchase price could be 170 euros.