I came to the conclusion a long time ago that in art as in life you get what you pay for.
Here in Spain we have a lot of shops that stock very cheap goods from China. You can buy anything from a plastic flower pot to an electric plug to superglue to a toaster. And everything is very cheap. The problem is that most of it only works once! And sometimes it doesn't work at all. These shops also sell art materials, and, once again, they are very cheap. But you get what you pay for.
A number of my students here in the art class I teach, come armed with boxes of paints that they bought for almost nothing. These boxes often contain a massive variety of colours, usually in very small tubes. My students get very excited about the bargain, But when then come to use the paints they soon find that they are awful, and they end up throwing them away and buying better quality. They really were not such a bargain after all.
Anyone who carries on using them just gets frustrated at the poor quality of the paintings they produce. There's always a wonderful 'light bulb' moment when I introduce then to artist quality paints, and immediately their paintings improve. They are no longer fighting their materials.
Artist quality paints can be expensive, but in my experience they are worth every penny. They are lovely to work with, they last a long time because they are not diluted with fillers, and they give you brilliant lightfast colours. And eventually they will cost you less, and you'll be a happier painter. What more could you ask for!