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

1. Current Condition: The coin has a condition of 75 (MBC), which indicates 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 is 226.81 euros, suggesting that there is a market willing to pay significantly higher prices than the starting price.
- In the past, coins with similar conditions (75) have sold for varying prices, but there are examples of auctions reaching up to 2000 euros (although this may be an exceptional case).

3. Starting Price and Average Starting Price:
- The current starting price is 45 euros, which is relatively low compared to the average hammer price.
- The average starting price of 63.33 euros also suggests that the current starting price is competitive.

4. Recent Trends: Recent auctions show that coins with conditions of 75 have reached hammer prices of up to 170 euros, indicating that there is interest in this price range.

Based on these factors, an estimated maximum purchase price for this coin could be in the range of 150 to 250 euros, considering that the condition is good and that the auction history shows hammer prices that can be significantly higher than the starting price.

Therefore, a reasonable estimated maximum purchase price could be 200 euros.