You are looking for dumping cell phone for cost, or you want the standard behavior of two-way radio: push to talk?
If you only need to talk a few miles, you can consider MURS for cheapness.
But if you need to talk around town, you need to use a repeater.
There are many options, such as nextel.
Or try your local commercial radio shop to see if they sell access to trunking system.
Or there is the old-school single channel repeater.