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

1. Coin Condition: The coin has a condition rating of 80 (MBC+), indicating that it is in relatively good shape. This can influence its value, as coins in better condition tend to fetch higher prices.

2. Starting Price and Previous Prices: The current starting price is 150 euros. In previous auctions, we have seen hammer prices that varied, with some reaching up to 440 euros in similar or better conditions. The average hammer price in the past is 145.82 euros, suggesting that the current starting price is reasonable.

3. Price Trends: Looking at the hammer prices from previous auctions for coins with a similar condition (80), the highest recorded price was 320 euros. However, it is also important to consider that the market can fluctuate and demand may vary.

4. Number of Auctions: The coin has been auctioned 116 times, with a high sales percentage (112 times), indicating a consistent interest in this coin.

5. Estimated Prices: Estimated prices in previous auctions for coins of similar condition have ranged between 150 and 200 euros, suggesting that the hammer price could be within that range.

Taking all these factors into account, an estimated maximum purchase price for this coin could be between 200 and 250 euros, considering that the interest in the coin and its condition are favorable. However, it is important to stay alert to the dynamics of the auction and the competition from other bidders.