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

1. Coin Condition: The coin has a condition rating of 70 (MBC-), indicating that it is in acceptable condition, but not among the best.

2. Auction History:
- The average hammer price for similar coins has been 76.12 euros.
- In previous auctions, coins with a similar condition (70) have had hammer prices that vary, but some examples are:
- 50 euros (2020-10-20)
- 70 euros (2022-03-10)
- 50 euros (2023-02-16)
- 50 euros (2022-10-18)

3. Starting Price and Average Starting Price:
- The current starting price is 30 euros, and the average starting price in the past has been 38.42 euros.

4. Price Trends:
- In recent auctions, the hammer price has ranged from 50 to 95 euros for coins of similar condition.

Based on this data, an estimated maximum purchase price could be set in a range between 70 and 90 euros, considering that the average hammer price has been 76.12 euros and that the coin's condition is rated at 70.

Therefore, a reasonable estimated maximum purchase price could be 85 euros.