Background: foxgloves in watercolor
cheap supplies can be high quality. learn pigment names and the materials which make up the supplies you are using. even some expensive paints may be formulated with fugitive colours. test out the paints you are using by painting them on different grounds and exposing them to intense sunlight and if possible smoke and moisture.
ralph mayer's handbook of artists' materials and techniques is available in libraries. i bought a copy around 1975. it taught me more about how to paint and where i can save money responsibly on supplies than any other book or person i have met. there are later editions, but you don't need the latest -- save money and buy it used.
the important thing is to use colours that remain stable over time. a number of cheap paints are not permanent. it is possible by judicious buying to find good buys in student grade paints. a number of earth colours are pretty stable. a more expensive colour like cobalt violet is hard to find in a reliable formulation in a cheap line. learn to do without a colour unless you can afford a permanent version. most really good painters used a restricted palette.
just because a paint is labeled with same pigment name does not mean it mixes with whites and yellows and other colours the same way another tube from another supplier of the same pigment name works. learn to test your colours by painting them out with different media and colours. some sienna formulations tint out or reduce to a greenish yellow, others to a rich golden flesh tone. it is easy to make muddy ugly colours by assuming that sienna is alike in workability.
it is also possible to use top quality archival materials in ways that fall apart quickly. i have seen too many paintings by academically trained artists where no attention was paid to conservation techniques. if you do not know how to construct a painting that will last then no amount of money spent on expensive paints will help. art proceeds from the ground up. it is possible to use cheap supplies yet produce high quality art.
melynda the frugal