Paintbrushes need to be a decent quality to a decent paint job. And quality paintbrushes aren’t cheap. But you can get years of work out of one brush if you properly clean it. Latex is a water-based paint, so you don’t need chemicals to clean the brush. It’s best if you have a utility sink to clean your latex paintbrush.
Turn the paint brush over and let a gentle stream of warm water run directly into the bristles while "squeezing" the bristles together. Continue this until the water is running almost clear out of the bristles.