All you need is some Jo Sonja acrylics. Cheap. High quality. Work perfectly.
Get base colours. Mix your own, and make some beautiful colours that nobody else has.
Save money. Win.
The industry doesn’t want you to know you can just mix your colours, just like every other artist out there does.
I think the only thing I would add is that if you are doing a large number of minis wearing uniforms (looking at you Warhammer folk), then I would mix my paint in large batches. Getting it exactly the same again might be a pain.