To estimate a maximum purchase price for the coin in question, we can analyze the provided data, especially the previous auction prices and the general trend of the auctions.

1. Current starting price: 2000 euros.
2. Average hammer price in the past: 541.79 euros.
3. Previous hammer prices: There are several hammer prices that varied significantly, with some reaching very high figures (for example, 2400 euros in 2019).
4. Condition: No information is provided about the condition of this coin, which may affect its value. However, it is noted that in previous auctions, coins with conditions ranging from 70 to 95 have had hammer prices that varied significantly.

Given that the starting price is 2000 euros, which is considerably higher than the previous average hammer price, it is reasonable to assume that the hammer price could be influenced by current demand and the quality of the coin.

### Estimation of the maximum purchase price:
- Based on the highest hammer price: 2400 euros (from 2019).
- Based on the starting price: If we consider that the starting price is an indicator of the seller's expectation, we could estimate that the hammer price could be in a range of 2000 to 2400 euros, depending on demand.

### Conclusion:
An estimated maximum purchase price could be between 2000 and 2400 euros, with 2400 euros being an upper limit based on the highest hammer price recorded in the past. However, since the starting price is 2000 euros, it is likely that the hammer price will not significantly exceed this value unless there is exceptional interest in the coin. Therefore, a reasonable maximum purchase price could be 2400 euros.