http://www.kensfish.com/testkits.html
my LFS petsmart had it on sale for $24
$21 at kens, only worth buying here if you buy other things to cover the shipping costs (ken's doesn't kill you on shipping charges)
petsmart now up to $30 so it comes out the same as ken's with shipping. it did have on sale a while ago for $24 which I happen to catch luckily.