DIY RO Unit (inexpensive option?)

[MicroTankin]

Gotta say that tip for that e-bay seller is A++, especially because the shipping is free and there is no duty (that is where e-bay can get ya). I hope he will still be selling in a year or so when I have enough money to set up a bigger system.....maybe I will ask for this for my birthday .

I have another question for anyone who is following this...
GlobalDesigns let me know about the water here in calgary and told me that all I need is a RO unit. Is there such a thing as a simple/cheap "1 stage" RO unit that would work well but be inexpensive?