There's no real need to hoard chemicals unless it's something totally obscure like technidol, which I sold for 10x what I paid 20 years ago, upon finding some cleaning my garage. Color might be another matter, but I don't know how that keeps.

For B&W, most of the common developers have competitive equivalents (like many of formulary's variety), or use "open source" style developers which are available both commercially and DIY (like pyro variants). Fixers are common chemicals and available from many sources as well. B&W chemicals are easy to acquire or mix.