Hmm.. I'll check out Costco next time I'm there.
I can't get a lot in Canada for my goats without going to the vet, and most the time they don't want to give it to you lol.
I was offering dairy cow minerals (we can't get goat minerals) which my co-op recommended free choice for a while but it wasn't working out that great, so then i started top dressing on their feed everyday, and now i've gone back to freechoice minerals lol. Make a PVC feeder for your minerals...
I totally recommend buying from a breeder, buying at least 2, etc.
Mine didn't come from a breeder, they came from someone who owned them as pasture pets. Mine are Pygmys, great size for a new owner, and I think something like a Nigi or a Mini Nubian would be great if you want milk