You should be able to find a door lock actuator at most stereo shops that install alarms. They run less than $20. You may have to fab a bit to get it to fit correctly but I'm sure it's cheaper than the dealer.
I would also encourage you to call rusty at Spartan, 1-800-349 4703 ask for parts. He has yet to let me down.
You can also check <a href="http://www.rockauto.com"target=top>Rockauto.com</a> for Part # DLA25. It's listing it at ~$48.00.