This is one of those fuzzy questions that are difficult to answer. Every person is different, especially the grade of work that they engage in. Or more specifically, the grade of standards. I can tell you what I use, but it may or may not be the right tool for what you do. Basically, I base every thing on price. Then use the highest tolerance tool applicable to what I am working on.
As a rule, building 1:87 models, I work within half a 64th inch,
give or take. Usually, a
vernier scale caliper is sufficient. As I age, especially the eyes, I become more dependent on
dial calipers. If I have a project requiring tighter tolerances, I will use a
B&S micrometer. There is a micrometer here that measures in 10ths, but I have only used it a few times over the 30 or so years I've had it. I bought it when times were flush and it was pretty, not because I needed it.
A dial caliper can be found on eBay, from $12 to near $100. Plus shipping, of course. I regularly purchase the low end calipers to give to friends, mechanics and the like. People to whom a 1/32 inch is problematic. That's 0.03125 inch... ... In those cases, accuracy is not that important. And a call you must make for yourself.
When doing cabinet work, for myself of course, a 1/32 error can be filled with paint. The norm is 1/64 of an inch. But that is unacceptable to one working on machinery, a full 0.015 plus a little. It all comes down to a couple of points, the primary one being just how tight you want to get the tolerances, The other being the brand of tool, Harbor Fright being near the low end of the scale, suitable for mechanics and framing carpenters.
My "advice" is like a butt hole, everyone has one and most of them smell pretty bad. I admire the "purist" that buys the best he can swing and only cries once. But I buy high end equipment only when I need it. Just never let it go, and doing so since the 70s, have quite a stock of good stuff that I don't use very often. But have it when I need it. My 10 cents worth, used to be 02 cents but inflation, ya know.
Bill Hudson