Anti theft key coding

I own a 2004 Dodge Stratus with 144k mileage. I have purchased another vehicle and was in the process of selling my Dodge. It was then broken into and the ignition cylinder lock seemed to be the only real damage. I didn't was to spend a fortune on a car I'm trying to sell so I purchased a new ignition cylinder lock and installed it myself. The car wouldn't start so I jumped it and it the electronics were once again functioning. When I tries to start it, however, it would run for a couple seconds and then stall out so I figured it was the battery. I changed out the battery (which is hell because it's under the wheel well) and it wouldn't even crank. I can now see it's due to the anti theft system and key coding... Should have read the manual first I guess. My question is how to get things recoded and the approximate pricing. I've done most of the 'hard labor' so I'm hoping this could be a relatively quick and inexpensive fix. The keys that were purchased with the new ignition cylinder lock are supposedly coded.