ON face value, I can see the value being added. THe key is: WIll you recover the costs in the 4 years you live there, at which time you'll sell your home? Assuming you will, then go for it.
As an aside, I just posted a reply on the New BBS to a guy looking to do something similiar. Are you familiar with Concrete Stamping? It's where concrete is poured and it is the colored AND stamped to 'look like' pavers, or even brick, or even slate, or even granite, or even wood (to name a few.) Assuming the existing patio is 'solid', it may be cheaper AND you can get a nicer look (if you want.)