I did one better, I grew my own trees for the wood. THat's why it took me years to get off my butt and build my first one.
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I'd say out of building your entire machine, the control panel tends to be the most complex part. There's a lot of woodworking, cutting/stripping wires, crimping, wiring, etc. That scares a LOT of people, and takes an immense amount of time. Someone can still design and build their entire cabinet and drop in a pre-built control panel and still get a great deal of pride out of what they constructed.
I can't tell you how many times I've considered just buying the UAII kit this time around since my UAII was destroyed in a move (cabinet blew apart after a mishap in the moving truck, I DON'T WANT TO TALK ABOUT IT!

. I'd still be damn happy with it.
I personally would rather build, but I think the most important thing this site does is expand the hobby, so if people want to buy, GO FOR IT. Keep the hobby going. Interest is the only thing that's going to drive new products, new frontends, and new innovations.