After switching to standing and seeing incredible gains in my body health, it's hard for me to consider spending on a good chair. I have a standing stool at the ready if I really need a rest, or at that point it means I need a break anyway. Oh and I started without a standing desk: just repurposed a piece of high furniture to find out if I can work this way. I was tired the first week but you quickly get to where sitting for long periods is unappealing!