Getting your feet wet in Amateur radio is fairly easy and if you'll just be doing local comm or bouncing off of repeaters, all you need is your Technician license and a UHF/VHF radio. The cost of the test is merely $15 plus whatever you invest in study aids.
A simple 2m hand-portable (think walkie-talkie) may be sufficient for hitting your local repeater and can be had for about $130-200 depending on what brand and model you get. I bought a Yaesu FT-270R hand-portable after the fact and spent all of $130 on it.
Portables usually issue about 5-watts power, which combined with the typical rubber ducky antenna limits you a bit on how far your signal is going to reach. A few miles, depending on terrain, typically.
Mobile UHF/VHF rigs can be had from about the same price range to upwards of $500 depending on how many bells and whistles you want. The Yaesu FT-7900R that I run in my truck only cost about $300. You also need to factor in the cost of your antenna, antenna mount, antenna coax, power wiring, etc. I think my rig cost me about $500 all together but I planned for future expansion and added in some things you could eliminate to save money.
If you want to talk to folks in other states / countries, you're going to want to pursue your General license (another $15) and invest in HF gear. The sky is the limit on the cost of the associated equipment and it all depends on how deep you want to get and how much you want to spend.