There are some bps in shops but most of the time it's plasma pistol, plastic explosives, dynamite, laser rifle, super cattle prod and drugs, usually in 3 or 6 stacks. I've yet to see P90c and .223 pistol. I heard people got combat armor blueprints from shops, don't know if that's true, I for one have never seen combat armor bps (and that's not so bad).
My view may be biased, I only shop in San-Fran, Boneyard, Hub, Junktown, NCR, Vault City.
Can we have more varied blueprints in shops?