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

1. Coin Condition: The coin has a condition rating of 75 (MBC), indicating that it is in fairly good shape, but not of the highest quality (FDC).

2. Auction History:
- The average hammer price for similar coins has been 166.58 euros.
- In previous auctions, coins with a similar condition (75) have had hammer prices that varied, but some examples are:
- 95 euros in an auction in 2018.
- 60 euros in another auction in 2018.
- 50 euros in an auction in 2020.

3. Starting Price and Estimates:
- The current starting price is 30 euros, which is relatively low compared to the average hammer price.
- The average starting price for similar coins is 65.53 euros.

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

Based on this data, an estimated maximum purchase price for this coin could be between 80 and 120 euros. This is because, although the average hammer price is higher, the condition and starting price suggest that a buyer might be willing to pay a bit more than the average hammer price, but not enough to reach the higher prices of better condition coins (FDC).

Therefore, a reasonable estimated maximum purchase price could be 100 euros.