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

1. Current starting price: 150 euros.
2. Auction history: The coin has been auctioned 10 times, of which it has sold 9 times. This indicates good demand.
3. Average hammer price: 94.56 euros, which is an indicator of what buyers are willing to pay on average.
4. Previous prices: Previous hammer prices varied, but there is a hammer price of 250 euros in 2015, suggesting that it has reached higher prices in the past.
5. Condition: There is no condition information for the current coin, which may make buyers more cautious. However, the history shows that there have been coins with varied conditions.

Given that the starting price is 150 euros and considering the average hammer price of 94.56 euros, an estimated maximum purchase price could be positioned between the starting price and the highest recorded hammer price.

Taking all these factors into account, an estimated maximum purchase price could be approximately 180-200 euros. This reflects potential interest in the coin, but also considers the lack of information regarding its current condition.