To estimate a maximum purchase price for the coin in question, we can consider several factors based on the provided data:

1. Current Condition: The coin has a condition rating of 70 (VF-). This is an important factor, as coins in better condition tend to reach higher prices.

2. Auction History:
- The average hammer price from previous auctions is 163.82 euros.
- The coin has been auctioned 14 times, of which it has sold 11 times, indicating good demand.
- In recent auctions, the hammer prices have been quite high, especially in the March 2023 auction, where it sold for 280 euros with a condition rating of 90.

3. Starting Price and Estimates:
- The current starting price is 150 euros, which is slightly higher than the average starting price of 124.62 euros.
- The estimated price of 150 euros is also relevant, as it indicates the seller's expectation.

4. Price Trends:
- In previous auctions, hammer prices have varied, but there are examples of hammer prices exceeding 200 euros, even with similar conditions.

Based on these factors, an estimated maximum purchase price could be in the range of 200 to 250 euros. This is due to the good historical demand, the hammer price in recent auctions, and the condition of the coin.

Therefore, a reasonable maximum purchase price could be 250 euros.