Ever since the assault weapon ban expired, I've been looking at getting a nice Bushmaster rifle with all the goodies installed. But after looking at their website, their ARs are fairly pricey. The standard Bushmaster 20" AR with preban features is $995 with an A2 upper.
However, if I were to buy the upper and lower receiver separately, it's a different story. The lower receiver, fully assembled and with a buttstock is only $295. And the matching pre ban upper configuration is only $535, this comes to a total of $830. That's a savings of $165, and for the exact same gun. It only takes about 5 seconds to join the upper and lower receiver.
The complete rifle comes with a 30 rd magazine and hardcase, but this doesn't cost $165, or even close. Not to mention, if I buy a lower receiver, I have better versatility for making my own rifle, not one picked for me. Does this make sense to anyone else?

Yup. And you'll save even more money if you buy them seperately also in taxes as you only need to have the lower receeiver shipped to a FFL holder so you'll only get taxed on its value.