If you're looking for a less expensive way to go check your local papers and bulletin boards at the lfs for used tanks, buy a piece at a time until you have alll you need. You'd be surprised at how cheap people are willing to sell the equipment that isn't being used anymore.
Just be aware that when you buy used you take your chances on the quality...and always test used aquariums and equipment for leaks before setting them up for fish.
Don.