Last I heard (I guess about 7 years ago) they were raking in $6000+ a night in Vegas. I thought they dressed up for that (maybe not... or I'm thinking of another Beatles Trib act).
Really though do that for a while, accumulate gear and you can write your own ticket/focus on the tunes.
Recreating music I liked note for note was my main interest. The rest was annoying to me but it got me around a bit and I learned a lot.