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 in lower conditions.

2. Current Starting Price and Previous Prices: The current starting price is 150 euros, and the average hammer price in previous auctions is 156.86 euros. This suggests that the starting price is aligned with the market value.

3. Auction History: The coin has been auctioned 24 times, of which it has sold 23. This indicates high demand and good interest in the coin, which can influence the price.

4. Previous Hammer Prices: Looking at previous hammer prices, there are several examples of prices exceeding 150 euros, especially in similar conditions. For instance, in 2022, a coin with a condition of 75 was sold for 220 euros.

5. Recent Trends: In the most recent auctions, hammer prices have shown a tendency to be higher, which may indicate an increase in demand or in the value of the coin.

Based on these factors, an estimated maximum purchase price could be in the range of 200 to 250 euros. This is based on the current condition, price history, and market trend. However, it is important to note that the final price may vary depending on competition in the auction and other market factors at the time of sale.