Dito. I have the Bekant (160cm * 80cm and adujstable height between 65cm and 125cm) at home which costs around 550 usd where I live (20% tax already included) and has 10 years warranty (most a lot more expensive desks have only 2-3 years). I can sit and stand at the desk but I sometimes use a sports trampoline for mild jumping or a treadmill to walk at the desk (like linus torvalds). [1]

Some studies suggest a 8 hour workday should consist of 60% sitting, 20% standing and 20% walking (no link at hand since I'm not at my regular pc).

In some countries Ikea has an even more affordable sit-stand desk called Skarsta. [2]

[1] https://www.youtube.com/watch?v=HSgUPqygAww [2] http://www.ikea.com/jo/en/catalog/products/S29084966/