Most of us have been there, but yeah I don't see red ones often at all, and definitely not for $20, but if you weren't ready passing on a gem is better than harming it, so you did the right thing, they are out there, be patient.
My last malu took 6months of searching.
Comb LFS, just don't expect they know what they have, you're going to have to know usually, usually the ringed stubby tentacles tell ya, but not all are ringed.