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

1. Current Condition: The coin has a condition rating of 75 (VF), indicating that it is in relatively good shape. This may positively influence its price.

2. Auction History:
- The average hammer price for similar coins has been 206.16 euros.
- In previous auctions, we have seen hammer prices that varied significantly, ranging from 57 euros to 1100 euros, depending on the condition and other factors.
- The last auction for this coin had a hammer price of 320 euros with a condition of 85, suggesting that the value may increase with better condition.

3. Starting Price and Average Starting Price:
- The current starting price is 70 euros, which is below the average starting price of 110.48 euros. This could indicate an opportunity to buy at a lower price.

4. Sales Trends: The coin has been sold in 19 out of the last 20 auctions, indicating good demand.

Based on these factors, an estimated maximum purchase price could be in the range of 250 to 300 euros. This is based on the auction price history and the current condition of the coin. However, since the starting price is 70 euros, it may be possible to acquire it at a lower price, depending on the competition in the auction.