This is one of those times when you get what you pay for. Cheaper roller covers don’t perform as well as the expensive ones.
We like Purdy White Dove for interior house painting. We have tried a few others but it is hard to argue with something that works well.
There are some applications where a cheaper roller cover can work – ceilings and textured surfaces are examples. However the really cheap roller covers do not hold paint as well and make for more work loading the roller with paint.
If cleaned well after use (which takes time) a good roller cover will last longer than a cheap one and will pay for itself.