With eggs and meat or shellfish you should get a decent amount already. Then you can complete with gelatin and whatever dairy you tolerate. Have you tried non-hydrolyzate gelatin? That could be a lot cheaper than the great lakes green tin, and a few testimonials indicate that it's more potent than hydrolyzate. Try preparing a gummy bear type recipe, mixing gelatin in a bit of cold water, then dissolve in heated coke or fruit juice, then let it harden. If you let it cool in a mug, you get a jelly cake which you can then eat throughout the day.