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

1. Current Condition: The coin has a condition rating of 75 (MBC), indicating that it is in quite good shape. This generally translates to a higher price compared to coins with lower conditions.

2. Auction History:
- The average hammer price for similar coins has been 84.45 euros.
- In previous auctions, we have seen hammer prices that varied significantly, but some relevant examples are:
- A coin with a condition of 80 was hammered at 120 euros.
- Another with a condition of 85 sold for 130 euros.
- A coin with a condition of 70 sold for 54 euros.

3. Starting Price and Average Starting Price:
- The current starting price is 70 euros, which is below the average hammer price of 84.45 euros. This suggests that there is potential for the hammer price to be higher.

4. Recent Trends: In the most recent auctions, hammer prices have shown an increase, especially for coins in good condition.

Based on these factors, an estimated maximum purchase price for this coin could be between 100 and 130 euros, considering its good condition and the hammer price history of similar coins. This would allow for a competitive bid without exceeding the market value observed in previous auctions.