Just some considerations.

Can you wait for a rebate?

Often, you can get pretty good deals on hard discs with rebates.  My 80G 
Maxtor cost $50 after a 50 dollar one, and I've seen larger drives for the same 
price after offers.

Video card?  Taken care of?

The $24 case probably features a power supply manufactured by the Hak Foo 
Industrial Power Supply and Shrimp Company.  It may also not have as nice 
fit-and-finish.  Many Antec cases are, however, made by other firms