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 an acceptable state, but not among the best conditions. This may affect its value compared to coins in better condition.

2. Auction History:
- It has been auctioned 10 times in the past, of which it has sold 8 times. This indicates good demand.
- The average hammer price in previous auctions is 303 euros, suggesting that, in general, buyers are willing to pay close to this price for similar coins.

3. Starting and Hammer Prices:
- The current starting price is 150 euros, which is significantly lower than the average hammer price of 303 euros.
- In previous auctions, hammer prices have varied, but there are examples of sales above 300 euros, especially for coins in better condition.

4. Price Trends:
- In the 2013 auction, a coin with a condition of 80 sold for 650 euros, indicating that there is potential for high prices depending on demand and condition.

5. Comparison with Previous Prices:
- The last auction with a similar condition (75) had a hammer price of 200 euros, which can serve as a reference point.

Taking all these factors into account, an estimated maximum purchase price for this coin could be in the range of 250 to 300 euros, considering that the average hammer price is 303 euros and that condition is a limiting factor. A price of 275 euros could be a reasonable target, as it falls in the middle of this range and reflects the price trend in previous auctions.