Very good advice from others, with which I fully agree. Skimping on chemistry is rarely economical yet often very frustrating. On the other hand, depending where you live, you should consider reusing some of it, and minimise waste, within reason. What concerns me, is the disposal. In many parts of the world, it is ok to dispose into a public waste system, and one-shot use is easy to justify and enjoy. On the other hand, if you live with a septic tank, or if your local regulations are strict, you may need to minimise waste, or your hazardous waste disposal bills/trips will mount.

I reuse a long-lasting print developer (Ansco 130), indicator stop-bath (till it starts changing colour), and fixer (till test strips indicate it needs changing), HCA (based on a count of processed sheets), and Se toner (till it slows down a lot). I do not reuse film developer, I use it one-shot. I also use Silver Magnet to recover some silver from the fixer, before disposal.

Enjoy your darkroom, very much.