But what if, instead of buying the domain name, you... didn't buy it? What if, instead of dropping $5K on an exact match, you spent $10 on a B+ domain name, where you can set up a landing page to see if there's interest in the business idea you've generated?
That way, if you are getting signups, or even actual customers, then you try to get a better domain name; but if not, you're not out $5K.
Or am I missing something? I guess you can still sell the domain if you don't end up doing something with it, but what if it declines in value?
edit: punctuation