I finally realized a shoe shelf would do it. I think I paid $20 CAD for it. I think it's half the price in the US. It looks as cheap as it costs though. Originally I thought it would be a stepping stone to a Varidesk, but now I realize I can get away with a stand-only setup if I just got a stool.
FWIW, I just bought the stool a couple of weeks ago, so it took me around a year of standing to pull the trigger.
I've been looking at chairs for a while, but like you said, they can get expensive (I had my eye on the Humanscale Pony Saddle [1]). I don't sit for long periods of time on the stool, just here and there to take the weight off.
At $60 CAD, I figured the Ikea Nilserik was probably a low risk purchase compared to something >= 2X the price. You obviously get what you pay for, but if you're not planning to sit most of the time, it works out fine.
[1] https://www.humanscale.com/products/product.cfm?group=Freedo...
You know what's funny. A lot of those tall chairs cost $100-150ish. I actually contemplated buying a cheap $200ish laptop instead of a chair, simply because the laptop has much more utility. Then I would just sit with a normal chair and use the laptop for breaks.
My plan was to wait a month or so and see how things panned out before buying anything for sitting. So far I don't feel like I need one.
Haven't ran into any deep thinking issues lately. Currently I'm in the middle of planning an online course out which does require some thinking but I haven't noticed it being harder to think while standing.
At the start it definitely affected me when all I could think about was how bad I wanted to sit.