1) You never save money building it yourself (at least not in comparison to a standard consumer option, like a chair or table from your local furniture store. This may hold up if you compare what you build to high-end hardwood furniture. But with the cost of tools, you're probably still losing money if this is just a hobby)
2) 90% of my enjoyment of woodworking is just being in my shop working. The results are almost secondary. It's a hobby for a reason.
3) I know professional woodworkers and they definitely do not spend most of their time building organization. They buy anything that will speed up production. I can spend 6 months building a dream workbench, they'll go to Benchcrafted and just buy one.