You're argument is flawed because someone is going to come along and say "$200 isn't enough to really test most advertising methods...I'd throaw at least $20,000-$100,000 on testing something." Then along comes Procter and Gamble and they say $10m-40m. It's all about scope and market size.
Is the market for music small? Was he testing in some specific genere, geographic region or other targeted group to justify the smaller budget?
There comes a point where you need a minimum amount of money before you can tell if something is working. If you spent 10 cents on advertising, that would be pretty meaningless.
I operate e-commerce businesses, and I'd throw at least $500-$2,000 on testing something new before I call it quits.