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 (VF+). This is an important factor, as coins in better condition tend to fetch higher prices.

2. Current Starting Price and Previous Prices: The current starting price is 1250 euros, and the average hammer price in previous auctions is 1383.54 euros. This suggests that, in general, coins of this reference tend to sell for above the starting price.

3. Sales History: The coin has been auctioned 46 times, of which 42 have been sold. This indicates good demand and a history of successful sales.

4. Previous Hammer Prices: Looking at previous hammer prices for coins with similar conditions (80 to 90), we can see that hammer prices have varied, but generally, coins in VF+ condition have reached hammer prices ranging from 950 to 1600 euros.

5. Recent Trends: In the most recent auctions, hammer prices have been in the range of 1300 to 2200 euros for similar conditions, suggesting there is potential for an increase in the hammer price.

Based on these factors, an estimated maximum purchase price could be around 1600 to 1800 euros. This is based on the history of hammer prices and the current condition of the coin. However, it is important to keep in mind that the final price may vary depending on competition in the auction and the interest of other buyers.