Unless you're running Prepaid (for how little it matters), there is no difference between using 3g and the cell network in term of price..you're still paying for X minutes per month. The only question is weather you will use those minutes. Still, the minimum plan you will get is $60+ per month (not sure on the 3g costs) with 450 minutes (I believe...). So unless you're being REALLY picky about your minute usage, it really doesn't make a difference.You've got to be kidding.. how many normal users do you think even know what VOIP is? Only a tiny percent of people use VOIP, let alone on a mobile phone. Why dont Apple the nanny company protect me from watching 100mb worth of youtube videos on a 50mb plan (like one of the iphone plans here in australia)?
They dont allow VOIP over 3g because it bypasses the carriers call costs... its very obvious. Especially in the USA with unlimited data plans, thats a SHITLOAD of extremely cheap calls that could be made over 3g.
I consider myself a heavy phone user (business, etc.), and I don't go anywhere near my 200 minutes a month (unlocked, running ATT PYP), and I don't use VOIP. This phone is the only one I ever use to talk to people. Unless you KNOW you are going over your monthly balance...VOIP doesn't mean anything.