For under $500, a better solution would be the new IKea Bekant motorized standing desk. We just got them for all our developers and they are great. And given that it's an Ikea product, you still get a similar DIY experience when assembling it.
Were you able to find these in the US?
If you are not near an Ikea and can't think of an excuse to do a day road trip to the nearest one, you might consider some of the motorized/adjustable desks on Amazon (just search for those terms).