I had to replace my starter a couple of months ago. If your radio and lights are still working, that does sound like the starter.

You have a couple of options. Most of the time when a starter goes south, its just the contacts inside that are busted. I had a shop replace those contacts for $39, and my car now starts like a dream. You can buy a new starter, but that runs about $150. It's not too hard to replace the starter yourself, but you do need to remove the stock air intake to get to it. I have a CAI, and it was kind of a ***** to get to without taking that off, but I eventually managed.