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. Previous Auction Prices:
- The average hammer price from previous auctions is 332.22 euros.
- The last auction with a similar condition (70) had a hammer price of 170 euros, indicating that the market may be willing to pay less for coins in similar conditions.

3. Starting Price and Average Starting Price:
- The current starting price is 175 euros, which is lower than the average starting price of 235 euros. This could indicate that there is an opportunity to buy at a reasonable price.

4. Sales Trends: Out of the last 10 auctions, 9 resulted in sales, suggesting that there is consistent interest in this coin.

5. Previous Estimates: In previous auctions, estimated prices have varied, but generally, hammer prices have been higher than the starting price.

Taking all these factors into account, an estimated maximum purchase price could be in a range between the average hammer price (332.22 euros) and the hammer price of the last auction with a similar condition (170 euros).

Therefore, a reasonable maximum purchase price could be around 300 euros. This reflects a balance between the coin's condition, market interest, and previous hammer prices.