The lowest price I've ever seen a 2 letter .com on sale for was qn.com at $7,500. I think this was in 2001. At the time people thought this was a lot for a two-letter starting with a "q". I wanted to buy it and did my sums and found I would have to go into an uncomfortable amount of debt to buy this and so didn't. $7,500 in 2001 was worth $10,000 today. Would you spend $10,000 on a decent 3-letter .com today? You probable don't have $10,000 lying in a savings account and would have to borrow at least some of it. So you'd probably say no. But in five years today's $10,000 3 letter .com might be worth what 2 letter .coms are worth today and you would make huge profit.
I think a more typical price in 2001 was $12,500 for LQ.com and this was bought at this price by an end-user.