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

1. Starting price: 900 euros.
2. Condition: 95 (EBC+), indicating that the coin is in very good condition.
3. Auction history: The coin has been auctioned once before, with a hammer price of 900 euros, which matches the current starting price.
4. Previous estimated price: In the previous auction, the estimated price was 1000 euros, but the hammer price was 900 euros.

Given that the coin has a history of successful sales at 900 euros and considering its high condition (95), it is reasonable to think that interest in the coin could remain stable or even increase, especially if there is more demand in the current auction.

Estimation of the maximum purchase price:
- Since the previous hammer price was 900 euros and the estimated price was 1000 euros, a maximum purchase price could be set between these two values.
- Considering the condition and potential interest, a reasonable maximum purchase price could be 1000 euros.

This allows for a margin for competition in the auction, given that the starting price is 900 euros and there is a history of interest in the coin.