In addition to my response to 300lbs of get down, if you're promoting a concert and wish to host one or more national act, be prepared to spend big for staging, sound, lights, power, security, stagehands, insurance, an appropriate venue, catering and hospitality for acts and crew, beer and liquor sales for audience, and a host of other things... If you're not willing to do it right, if you're trying to do a show on a shoestring budget, stop now.