To estimate a maximum purchase price for the coin in question, we can analyze the provided data, especially the previous auction prices and the current condition of the coin.

1. Current Condition: The coin has a condition of 75 (MBC), which is an average condition. This suggests that its value will not reach the higher prices seen in coins of better condition.

2. Previous Auction Prices:
- In previous auctions, coins with a condition of 75 have reached auction prices that vary considerably. For example:
- In 2011, a coin with a condition of 75 was auctioned for 420 euros.
- In 2013, another coin with a condition of 75 was auctioned for 250.03 euros.
- In 2014, a coin with a condition of 75 was auctioned for 821.62 euros.
- In 2015, a coin with a condition of 75 was auctioned for 400 euros.
- In 2022, a coin with a condition of 90 (better than 75) was auctioned for 270 euros.

3. Average Auction Price: The average auction price for similar coins is 212.49 euros, which can serve as a good indicator of the expected value.

4. Starting Price: The current starting price is 75 euros, indicating that the seller expects a lower price initially.

5. Auction Trends: Given that the coin has been auctioned 56 times in the past and has sold 44 times, there is good demand for this coin, which may increase its value.

### Estimation of Maximum Purchase Price:
Considering all these factors, a reasonable maximum purchase price could be in the range of 200 to 300 euros, considering that:
- The condition is 75, which limits the maximum price.
- Previous auction prices for coins with the same condition have reached up to 420 euros, but that is an exceptional case.
- The average auction price is 212.49 euros, suggesting that a purchase price around 250 euros would be competitive and reasonable.

Therefore, an estimated maximum purchase price could be approximately 250 euros.