Yes you can get a kit, but none I've ever worked with made the cost worth it. I've seen some from Samson and AT and yes they cost lest, but usually all they contain is some tom mics and some mics that 'say' they're for snare or kick but rarely do them justice.
I think you can get the mics you need without buying a kit... get some 57's or e604's for your toms and they'll be better than most of those Nady or other mic kits... you can pick up a few at 50 bucks each... and for a kick mic get a used D112 or Beta 52 for 125 or so... overheads get yourself a matched pair like the Oktava MK012's or the MXL 603s...and for snare you can use a 57, or if you want try a Beyer M201 - you won't regret that...
total: toms 150, kick 125, overheads 200, snare 50-150 = $550-650
if you have to skimp on cash, I would say skip the toms and get a kick, a snare and a pair of OH's...that's 400 now...and you'll get great results if all you're doing is demo work.
Jacob