Let's talk about art materials. They are quite expensive and some tend to accumulate in the studio unused, which is a waste that few can afford. So, here is what I found can go wrong with materials, and how to avoid waste. Since I mostly paint with acrylics, that's where I have most information to share, but lot of this applies to any medium.
Can we use student-grade paint?
If you can paint well with student grade paint, I am truly impressed. I can't. I tried Liquitex Basic, Windsor Newton student acrylics, and Pebeo brand. My plan was to have big juicy amounts of cheap paint to play with. However, I ended up using them only for the imprimatura (to to tone down the canvas before starting the under-painting). Painting with student grade acrylics feels to me like painting with bubble gum with vague traces of pigment. On the other side, Pebeo is so scarily opaque that even the transparent pigments like burnt sienna can't be made transparent even with a huge amount of medium. I now only use Pebeo black to paint canvas edges.
Do all brands of paint perform the same?
Golden brand is artist grade, and it's very popular because it's slightly cheaper than other brands, it comes in a huge variety of pigments, and it's available everywhere, together with a large variety of mediums, gels, texturizers and other additives. No other brand offers so many different colors as Golden. But my experience is that Golden pigments sometimes vary from batch to batch, and the consistency varies with pigments. For example, Green gold and Quinacridone Gold Yellow harden in the tube a few weeks after opening. I also dislike their tubes because of the tiny screw-tops that warp and become useless, same thing with W&N tubes. Also squeezing the last drops from malformed aluminum tubes is a drag.
Titanium white by most brands is way too transparent so you need many layers to achieve opaque white passages. I tested many brands and Liquitex is the most opaque acrylic white I have found. Liquitex paint also has lovely plastic tubes with great big screw-tops that you can use to stand the tubes upright - I love that. Liquitex sells a product they call "acrylic medium and varnish" which is awesome - it's more transparent and dries harder than equivalent products by any other brand I tried, although at some point I got a few bad batches that behaved more sticky than normally. But, that may also be due to the humidity, temperature and what not.
Should we buy big jars of paint?
Buying paint in jars is always cheaper, but it will only work if you paint fast. If your jars don't get used up within couple months, you need to be extremely hygienic when you take paint out (always use clean, dry palette knife), or the paint will go moldy. If you open them up too often, the paint will dry, or become lumpy, so you won't be able to use it all up, and you'll end up with waste rather than savings.
If you buy bulk jars of acrylic paint (especially if it's on sale), you may not get the same stuff that you buy in tubes. For example stay away from bulk sales of jars of Golden ochre yellow and burn sienna because they seem muddy and way too opaque - at least the last batch that I bought at a bulk Opus sale. Their other pigments that I bought in jars were fine.
What other cheap materials can be useful?
I generally buy the best quality materials and supports for my studio paintings, but I sometimes get canvas panels, cheap gesso and inexpensive paper palette's from Michael's for experimenting.
Canvas canvas panels are great for trying out techniques, I have no objections to them at all.
Cheap gesso is ok, but it's not as white as good stuff, so you'll need more layers. It can also be very gummy to the extent that it's difficult to pour out from the container, but once you dilute it with water it can be used just fine.
Cheap paper palettes roll up when wet which is very annoying, so I don't recommend them.
Canvases must be of the very best quality. Don't ever, ever buy bulk canvases on sale, even by the well respected brands. I had bad experiences with this. Cheap canvases are substandard, often banged up, dimensions are not accurate and some are not even rectangular but all warped up and distorted. I ended up having to re-stretch several paintings when I discovered that none of them fit into standard frames.
Cheap brushes are not worth a mention. My one attempt to use some cheap brushes ended up violently. You don't need that kind of thing in your serene studio.
Rags for glazing and wiping brushes are one thing you can easily save on. I am still too cheap to buy rags, so I cut up husband's old t shirts which work great, although I can get in trouble when he finds out that some of his favorite oldies ended up this way.
My conclusion is that cutting corners always brings some sort of frustration, and very often ends up with waste rather than savings. This was a very expensive lesson to learn, so hopefully my experience will save you a few dollars and a load of frustration.