I dont think silversides should be too expensive on the west coast, I know San Fransisco bay brand sells prepackaged ones in all different sizes and so do most other frozen fish food distributors. Also, one thing I noticed when trying to get rays to eat "salty" frozen foods (anything that originates in saltwater) is to soak thoroughly and rinse off with freshwater for a bit rather than just thawing them. Otherwise the rays seem to immediately "smell" the saltiness of the food and will not attempt to taste it. At least in my experience.