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

1. Current Condition: The coin has a condition rating of 80 (MBC+), which is a relatively good level. In the past, coins with a similar condition have reached auction prices ranging from 850 to 1300 euros.

2. Auction History: The coin has been auctioned 30 times, of which it has sold 27 times. This indicates good demand. The average hammer price in previous auctions is approximately 977.12 euros, providing a benchmark.

3. Starting and Hammer Prices: The current starting price is 1500 euros, which is higher than the average starting price of 884 euros. However, in previous auctions, coins with similar conditions have had hammer prices that varied but generally do not exceed 1300 euros in most cases.

4. Recent Trends: In the most recent auctions, hammer prices have been in the range of 1300 euros for similar conditions. This suggests that the market is willing to pay higher prices, but it also indicates that the starting price of 1500 euros might be a bit optimistic.

Based on these factors, an estimated maximum purchase price could be around 1300 euros, as this is a price that has been reached in previous auctions for coins of similar condition and reflects market trends. However, if interest in the coin is high, there may be room for a bit more, but 1300 euros seems to be a reasonable limit.