Antifreeze leak

I own a 1999 Plymouth Neon. Recently, when I was filling the overflow tank, the anitfreeze was leaking out of the bottom onto the driveway. I checked the radiator itself and it is okay. The car is not smoking and I dont smell antifreeze in the car itself. Also, the check engine light just came on. Sometimes when I start the car it acts like it wants to stall but doesnt. Then when It gets started its okay. Could it be a broken hose or something worse and what is an average cost to fix it? I kinda broke and cant afford to pay too much.