Meh, I think it's nice trend to see people re-creating the instruments most scientists treat somewhat as black-boxes, but having a thermocycler built with 21st century aesthetics doesn't really enable anything that you couldn't already do with a used $200 machine from ebay. And that's still pretty little.

Between reagents and a good collection of basic instruments, you're still looking at thousands to tens of thousands of dollars for even a minimal lab setup. It's not unfeasible to set up a garage lab, but it's also well outside most teens / early adults' budgets.

Some people have proposed microfluidics as a solution to lowering the cost by shrinking everything down, but that has yet to be proven practical as a general solution for biology. Most attempts to miniaturize existing protocols end up being their full-fledged research projects, and usually when you zoom you from the tiny plastic chip, you see hundred-thousand dollar microscopes / lasers / fluid control systems.

When it comes down to it, most lab instruments rely on pretty simple electronics / mechanics. A plate reader is a laser, a sensor, and a bunch of motors to move things around. A PCR machine is a heat pump, qPCR a heat pump plus laser and sensor. But the actual material selection, design, manufacturing, and quality control end up bumping up the price outside of the amateur's price range.