Based on the provided data, we can conduct an analysis to estimate a maximum purchase price for the coin in question.

1. Starting price: 6000 euros.
2. Average hammer price: 7000 euros.
3. Condition of the coin: 95 (EF+), which is a high condition.
4. Auction history: The coin has been auctioned once before, with an estimated price of 3000 euros and a hammer price of 7000 euros.

Given that the condition is high (95) and the average hammer price in the previous auction was 7000 euros, we can consider that the interest in this coin is strong, especially since it has sold for that price in the past.

Additionally, the fact that there have been no failed sale attempts in the past suggests that there is an active market for this coin.

Estimation of the maximum purchase price:
- Since the average hammer price was 7000 euros and considering that the coin is in similar condition, a reasonable maximum purchase price could be in the range of 7000 to 8000 euros, depending on the demand in the current auction.

Therefore, an estimated maximum purchase price could be 8000 euros.