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

1. Current Condition: The coin has a condition of 80 (MBC+), which indicates that it is in relatively good shape. This can positively influence its price.

2. Historical Prices: By looking at previous auction prices for coins with similar conditions, we can see that:
- In 2019, a coin with a condition of 95 sold for 240 and 280 euros.
- In 2018, a coin with a condition of 85 sold for 260 euros.
- In 2018, a coin with a condition of 80 sold for 140 euros.

3. Average Auction Price: The average auction price for this coin is 191.3 euros, which gives us a good reference for what buyers are willing to pay.

4. Starting Price: The starting price is 180 euros, suggesting that the seller expects a reasonable price based on previous auctions.

5. Recent Trends: In the most recent auctions, the hammer prices have varied, but there are examples of coins with similar conditions that have reached higher prices.

Taking all these factors into account, an estimated maximum purchase price could be around 250-300 euros, considering that the coin's condition is good and there are precedents of higher prices in previous auctions. However, the final price will depend on the demand at the time of the auction.