Well, the question has already been accepted, however. I'll mention something regardless.
First of all, it's perfectly fine to use a plain threaded rod for linear motion. You mostly simply need to consider what your basic requirements are, and your willing budget.
What I'm most surprised about, is that no-one here even considered to mention all the ways you can use ingenuity to solve the problem when money is a limiting factor. This was the common factor amoung ALL of the thousands of shitty 3d printer designs over the years, who all used threaded rod for various movements, and came up with tonnes of things to correct issues (like backlash). Some of them using software solutions or mechanical ones.
But first to list what you want:
- Linear movement, +/- 0.5mm precision
- Cheap
If you want to easily cheat, without spending any money at all, but are willing to get dirty, you simply go dumpster diving for old printers. They all have linear rails and different movement stages, some (most) have belts and pullys, some high end ones may have proper lead screws. Sometimes you can find really great parts from just old machines thrown away. There are countless backyard engineers who have made entire CNC machines using garbage they found.
This one of my favourite examples
The next option is to consider which standards you're up against. Zinc coated threaded rod is really junk...But A4 stainless steel metric rod is much better. It's tolerances are much smaller and it's quality is generally very high while still being fairly cheap..
But you say, what about the backlash?
Well bachlash is a problem regardless of which screw system you use, even leadscrews can suffer from them (why do ballscrews exist?) So how have people over the years corrected for backlash at all?
Well there are tonnes of tricks for this.
Have a look at some mechanical libraries (never invent things twice if you don't have to, mech engineering has barely changed for hundreds of years, someone has probably already invented what you want to do)
KMODDL
Digital Mech Library
Here is a search result for "backlash"
As quick tip, consider if you have 2 nuts on your rod that are tightened slightly in opposite directions on your rod....they can't have play if they are mechanically forced against that play can they?
Ofc there are problems with that...more friction, etc...but then we have oil right?
I also suggest becoming a regular reader of "hackaday.com"
There are tonnes of great ideas on there.
Some search results there
Threaded rod
Backlash