To estimate a maximum purchase price for the coin in question, we can analyze the provided data, including the starting and hammer prices from previous auctions, as well as the condition of the coin.

1. Current starting price: 500 euros.
2. Average starting price in the past: 298.86 euros.
3. Average hammer price in the past: 411.32 euros.
4. Hammer price history: Hammer prices have varied, with a range from 230 euros to 800 euros, depending on the condition of the coin.

### Analysis of previous prices:
- The coin has had a maximum hammer price of 800 euros in a previous auction with a condition rating of 95.
- Most hammer prices fall between 250 and 460 euros, with a trend to increase based on condition.

### Considerations:
- The condition of the current coin is not specified, making it difficult to determine its exact value. However, based on the price history, it seems that coins in good condition (80-95) tend to reach higher prices.
- Since the starting price is 500 euros, which is above the average starting price and the average hammer price, this suggests that the coin may be in a condition that justifies a higher price.

### Estimation of the maximum purchase price:
Taking into account the highest hammer price (800 euros) and the average hammer price (411.32 euros), a reasonable maximum purchase price could be positioned between these values.

Final estimation: A maximum purchase price could be approximately 600-700 euros, assuming that the coin is in a condition that could be in the mid-high range, given the starting price and auction history.