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

1. Current Condition: The coin has a condition rating of 80 (MBC+), indicating that it is in relatively good shape, but not among the best qualities (FDC).

2. Starting Price: The starting price is 1500 euros, which serves as a baseline for the auction.

3. Sales History:
- The average hammer price in previous auctions is 4632.75 euros, suggesting that, in general, coins of this reference tend to sell for significantly higher prices than the starting price.
- The coin has been auctioned 41 times, with 37 sales, indicating a consistent interest in this coin.

4. Previous Prices:
- There are several previous hammer prices that vary considerably, ranging from 850 euros to 32000 euros, depending on the condition and other factors.
- The last auction with a similar condition (80) had a hammer price of 2500 euros.

5. Recent Trends: In the most recent auctions, hammer prices have been in the range of 1800 to 2500 euros for similar conditions.

Based on this data, an estimated maximum purchase price could be set in a range between 2500 and 3000 euros, considering that the condition is good and that there is high interest in the coin. However, since the starting price is 1500 euros, it is likely that the final hammer price will be closer to this upper range.

Therefore, a reasonable estimated maximum purchase price could be 3000 euros.