It isn't just the studs, there are a lot of considerations. First of all, the electric code in your area is going to treat your metal studs with a whole different flavor than the wood ones. The cost savings on metal studs could be lost on extra labor to figure out how to install them, cut them, etc. It could also be lost on added electrical system expenses.
Beyond that, metal studs have different noise properties than wood. A metal wall sounds different.
Locating a stud for hanging a picture can be interesting too. My studfinder will tell the difference between a stud and a pipe, but not if they are both metal.
You will find that your plumbing systems should be insulated at every stud penetration, or you will hear every drop.
Metal studs have their advantages, they don't know what dryrot is, and they don't twist and warp after installation if they are "green". (unlike wood studs)
it's up to you, my point is don't make your decision on cost alone. Think about EVERYTHING that they will come in contact with in your project, and consider how they will affect it in terms of performance, installation, and cost.