Purchase a set of standards for your micrometers. I purchased mine from an industrial tools company. I check the "zero" before I start fitting engine components. Make sure the standards and the mikes are at the same temperature. Don't store mikes with the gap closed. It's a heating/cooling, expansion/contraction thing. The same holds true for calipers and bench vises.
The brands mentioned are good. I purchased some of my tools from pawn shops too. I may be crazy but I use a digital caliper and an infra-red heat gun (thermometer) I purchased at Harbor Freight.
The key is learning how to use the tools. Practice holding and reading micrometers by measuring feeler gauges. Same for a caliper.
I suggest storing measuring tools in a separate tool box.