Not sure that you'll actually save money doing it, but pouring your own soft plastics can be fun. Also lets you change colors/sizes to better match where you are fishing. Some commercial soft plastic baits you can melt down when they tear up. Something to try outside with a specific bait before doing a bunch. I believe the ones with salt in them do not melt so well. I do all my plastic melting outside so I don't stink up the house. Check out lurecraft.com for molds and supplies.
Andrew