It doesn't have to be. I put together my own. Here is what I purchased:

Jarvis Stand Desk Frame Only ($445) Home Depo Door ($60) Confidence Power Plus Motorized Electric Treadmill Black ($200)

So total of $700~ for basics.

Additionally, to make it look nice I added: WireTamer Cable Trays ($20) Shelf and Drawer Liner Wood Grain (x3 for a total Of $27) LED Lights ($20) Drill-able Cable Clips (x2 for $10) Belkin Power Strip ($22)

Since the higher position meant I started getting hit by the AC stream and I also didn't like people being able to see me through the windows when standing, I added: Frost King Air Deflectors ($10) Gila Privacy Window Film ($30)