By my back-of-fag-packet calcs you'd have to be getting at least £312 per person per gig to make it worthwhile it being your only job (assuming equivalent to 37.5h/wk job @ nat min wage of £10.42 = equivalent annual salary of £20,280, divided by 65). I'm sure there's a lot more to it than this but on the face of it it doesn't sound a particularly attractive prospect from a financial point of view.