I just bought my kit a few months ago. First, check craigslist or other local ads. There are occasionally local homebrewers who are selling materials at a good price.
super cheap - you will find threads of guys getting food grade buckets from bakeries, etc. A few of the other items (siphon, airlock) are pretty cheap, but a bottling bucket will make you life easier.
Kits - I agree with another post that the prices are pretty similar. It seems that Austin, Midwest, or Northern Brewer have flat shipping and may have the volume of business to have prices a hair cheaper.
Style - There are a few differences in the kits and that is what is worth looking into. I got the better bottle NB kit. In part the 6 gal BB can be used for beer or wine kits. Midwest kit has a bucket for primary and 5 gal carboy for secondary for similar price. I just didn't want all of that stuff, yet.