Answer:
The answer is: Yes
Explanation:
The money Alice paid in 1985 ($20,000) is considered a sunk cost.
A sunk cost is money already spent that cannot be recovered.
So if Alice decides to buy the land or not, she will not recover a cent from the $20,000 she paid before.
Since the current price of the land is $110,000 and Alice can purchase it for $100,000, then she should buy it. She is going to earn a $10,000 profit.