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

1. Current Condition: The coin has a condition of 80 (MBC+). This is an important factor, as coins in better condition tend to reach higher prices.

2. Historical Prices: By looking at previous auction prices for coins with similar conditions (80 and 90), we can see that:
- In 2020, a coin with a condition of 80 was auctioned for 120 euros.
- In 2018, another coin with a condition of 80 sold for 55 euros.
- In 2022, a coin with a condition of 80 sold for 75 euros.

3. Average Auction Price: The average auction price for this reference is 172.45 euros, indicating that, in general, coins of this reference tend to reach higher prices.

4. Starting Price: The starting price is 25 euros, suggesting that there is considerable room for the final price to be higher.

5. Auction Trends: The coin has been auctioned 14 times, of which 12 have sold. This indicates good demand and sustained interest in this reference.

Based on these factors, an estimated maximum purchase price could be in the range of 120 to 150 euros, considering that the condition is 80 and there are precedents for sales in that range. However, given the average auction price of 172.45 euros, it is reasonable to consider that if the auction generates interest, the price could even exceed 150 euros.

Therefore, an estimated maximum purchase price could be 150 euros.