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

1. Coin Condition: The coin has a condition of 70 (MS-), which indicates that it is in relatively good shape, but not of the highest quality (PR).

2. Historical Auction Data:
- The average hammer price for similar coins has been 165.94 euros.
- In previous auctions, coins with a similar condition (70) have had hammer prices that varied, but some examples are:
- In 2018, a coin with a condition of 70 was sold for 15 euros.
- In 2022, another coin with a condition of 70 was sold for 28 euros.
- In 2023, it was sold for 25 euros.

3. Price Trends:
- The average starting price is 57.62 euros, suggesting that sellers are looking for higher prices, but the actual hammer price may be lower.
- The coin has been auctioned 70 times, with a high sales percentage (67 out of 70), indicating good demand.

4. Comparison with Previous Hammer Prices:
- Hammer prices for coins with a condition of 70 have varied, but have generally remained in a range of 15 to 28 euros in recent auctions.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 25 to 40 euros. This is based on the condition, previous hammer prices, and the overall market trend.