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

1. Condition: The coin has a condition rating of 95 (S/C-), indicating that it is in very good shape. This generally increases its value compared to coins with lower conditions.

2. Previous Prices: By looking at previous auction prices for coins with a similar condition (95), we find that in past auctions, the hammer price has been 220 euros (2018) and 190 euros (2017). This suggests that the market value for coins in this condition can be quite high.

3. Starting Price and Average Prices: The current starting price is 180 euros, and the average hammer price in the past has been 122 euros. However, given the high condition, it is reasonable to expect that the hammer price will be above this average.

4. Auction Trends: The coin has been auctioned 22 times, of which 16 have been sold. This indicates a consistent interest in the coin, which can positively influence its price.

5. Comparison with Estimated Prices: The estimated price for this auction is 180 euros, suggesting that the auctioneers expect the coin to reach at least this value.

Taking all these factors into account, an estimated maximum purchase price could be in the range of 220 to 250 euros, as this is the range of hammer prices for coins of similar condition in the past. However, given the interest and condition, a price of up to 250 euros could be reasonable considering the competition in the auction.