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

1. Current Condition: The coin has a condition of 80 (MS+), indicating that it is in relatively good shape. This suggests that its value should be in the upper range of previous auctions.

2. Previous Prices: Looking at previous auction prices for coins with similar conditions:
- In 2020, a coin with a condition of 80 sold for 130 euros.
- In 2021, another coin with a condition of 70 sold for 130 euros.
- In 2022, a coin with a condition of 80 sold for 150 euros.

3. Starting Price and Average Hammer Price: The current starting price is 140 euros, and the average hammer price in previous auctions is 134.76 euros. This indicates that the starting price is reasonable and could attract bidders.

4. Market Trends: Since the coin has been auctioned 44 times and has had a high sales percentage (41 out of 44), this suggests that there is consistent interest in this coin, which could increase its value.

5. Estimation Based on Condition and Previous Prices: Given that the condition is 80 and considering previous hammer prices, an estimated maximum purchase price could be in the range of 150 to 180 euros, as coins in similar conditions have reached those prices in the past.

Conclusion: An estimated maximum purchase price for this coin could be 160 euros. This price reflects a balance between the current condition, previous hammer prices, and market interest.