I am assuming that the rope is not literally in "half" otherwise you'd just tie some rope back onto it and be done.
How much rope is sticking out of it? I'd say as long as you have one inch or more, you can make your own "crimp" really cheaply.
Items needed: pliers, lighter or torch, rope, electrical tape (craft store ball and drill if you want to get tricky)
Take a lighter or torch and burn the end of the rope for a while. (be careful to avoid dripping flames...they will burn into skin or other stuff and stay hot for a long time)
Keep melting it until the end mushrooms out nicely. Then dip it in cold water to "set" that expanded end of the rope. Now you can take another piece of rope, tie a knot in the end, then overlap that rope with the new mushroomed rope and secure them with a few cable ties, pulled tightly with pliers.
(I'm just thinking of common stuff that may be laying around the garage and essentially be "free")
Then get a wooden ball at the craft store (a bag of 20 or so is about $2) Drill the hole out, slide the new rope through the ball, tie a knot and voila....like new.
Your cable ties may eventually break, but I would say you can get quite a bit of use out of it this way.
You probably should wrap your cable tie ends where they've been cut with a good bit of black electrical tape. That will help cover those cut cable tie ends, which can get sharp.
Good luck! Chris