" you can bet your bottom dollar that somebody is going to say that Joni is well aware of this "irony" and that her actions just emphasize the total neglect of the busker's music."

Why wouldn't someone say that? The wording of the last verse makes is patently obvious.

I will just about bet MY bottom dollar that you will now say that I'm wrong. I will also bet a nickel that you're just trying to pull people's chains. I won't bet a dollar on that; maybe you really are just a bit obsessive. : )