To estimate a maximum purchase price for the coin in question, we can analyze the provided data:

1. Starting price: 10 euros.
2. Auction history: The coin has been auctioned 9 times and has sold on all occasions, indicating good demand.
3. Average starting price: 24.88 euros.
4. Average hammer price: 61.88 euros.
5. Condition: There is no specific information about the condition of this coin, which may complicate the estimation, but we can observe the hammer prices of coins with known conditions.

### Analysis of previous prices:
- Condition 70:
- Hammer price: 35, 35, 65 (average: 45)
- Condition 75:
- Hammer price: 95, 65 (average: 80)
- Condition 80:
- Hammer price: 140, 65 (average: 102.5)

### Estimation:
Since there is no information on condition, we can assume that the coin might be in a state similar to the lower conditions (70-75).

- If we take an average of the hammer prices for conditions 70 and 75, we could estimate a hammer price around 45-80 euros.

### Maximum purchase price:
Considering the starting price of 10 euros and the history of hammer prices, a reasonable maximum purchase price could be in the range of 60-80 euros, given that the average hammer price is 61.88 euros and demand seems to be strong.

Therefore, an estimated maximum purchase price could be 75 euros.