Pretty sure I know what I sell products for
Wanna be cheap? I can do a 4 watt handheld radio for $160 or a 5 watt handheld for $200 which is also dust/water proof. Keep in mind thats JUST a radio, aka 'walkie talkie' which you would just hold up to your mouth and use. If you just wanted to do a headset to that its $100 extra and $32 for a coil cord to connect the two. That would be truly the budget setup.
Right now our special on the car to car addition to our intercom system is $375 normally $450. The intercom<-->radio connecting cable is $50 so I can sell you a 50watt mobile for yourself for $325. Thats a vertex VX2200 50 watt mobile, antenna mount with 17' cable and the antenna itself.