You can get a pull-up bar really cheap nearly anywhere. You can get one that you can put up and leave up, or get something like a "Door Gym" which you can put up and take down as needed with no hardware. Please consider getting one - pull-ups and chin-ups are worth the effort to learn for strength and appearance sake!
"It is better to keep your mouth closed and let people think you are a fool than to open it and remove all doubt." Mark Twain ;-)