I had a commercial truing stand made of aluminium and plastic. It is not rigid and not accurate, though it still could be accurate after some adjustment to the truing stand. Still, it is not solid and rugged. I decided to build one based roughly on the design and instead of aluminium, I intended to use one inch iron angle bar. That was the initial plan.
I had a few bicycle parts that I was about to throw away (actually sell it for scraps), when I thought why not turn it into a truing stand. All that were needed were there, just need to rearrange and assemble it plus some figuring on how to achieve it. Since I didn’t need to buy material for it, I started the project immediately in earnest.
First, I patched the holes on the bicycle frame, cleaned it and set it up for truing the rear wheel. The rear dropout cut and welded in reverse. Second, I thought about how to attach the fork to the frame for truing the front wheel. Third, I figured out how to set up the mechanism for concentric, straightness and centering guides. These have to be able to true a wide variety of wheel sizes. Last, adjusting the truing stand so that the wheel will be trued and centred on the truing stand and on any good bike frames. Truing is done while sitting on a stool or a chair. I must say quite comfy.
You really do not need to have a truing stand if you rarely do it. On the occasion that you need to, you can do it on the bike itself. That is just my opinion. As for my case, I have a small shop.