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

1. Coin Condition: The coin has a condition rating of 70 (MBC-), indicating that it is in relatively good shape.

2. Auction History:
- It has been auctioned 11 times in the past, of which it has sold 7 times.
- The average hammer price in previous auctions is 55.71 euros, suggesting that, in general, coins of this reference tend to reach higher prices.

3. Previous Auction Prices:
- In several auctions, the hammer price has reached up to 130 euros (in 2022), indicating significant potential for high prices, especially in good condition.
- Most hammer prices for coins with similar condition (70) have been in the range of 22 to 90 euros.

4. Starting Price: The current starting price is 8 euros, which is quite low compared to previous hammer prices.

5. Trends: Given that the average hammer price is 55.71 euros and considering that the condition is 70, an estimated maximum purchase price could be in the range of 70 to 90 euros, as this is a price that has been reached in previous auctions for coins in similar conditions.

Estimated Maximum Purchase Price: Based on the previous analysis, a reasonable maximum purchase price could be 80 euros. This sits at a midpoint between the average hammer price and the higher prices reached in the past, taking into account the condition of the coin.