I started off with a regular desk and instead of throwing out my old desk, I just bought a standing desk converter and I really like it. I alternate between sitting and standing throughout the day and it has helped significantly with my back pain. Here's the standing desk converter that I bought[0]. In hindsight I wish I started off with a high quality adjustable desk but I don't regret my path at all.
[0]: https://www.vari.com/varidesk-converters/for-desktops/