Finding a good reflow oven is frustrating. The Puhui T962 series units, available since 2014, were around $150, but they had wildly nonuniform temperature inside. I've had boards scorched at the center and failure to solder properly at the edges. There's an open source mod to those which makes them reasonably usable. New firmware that runs the cooling fan a bit during heating to distribute the hot air, and a proper cold end reference for the thermocouples.[1] With those mods, those things are usable. These things have been cloned in China; you'll see "T962" units that don't have a Puhui logo on Amazon and eBay. None of the cloners seem to have made these well-known improvements and delivered a good out of the box experience.

The next step up costs much more. A nice little prototyping convection oven from Germany costs about $3500. There's not much in between the $200 units and the $2000 units.

The article is really an ad for Whizoo's Controleo3 board, which is $249 with all the parts you need. So this isn't that great a deal.

Most of the cheap solid-state relays on eBay and Amazon are fake. The current ratings on the unit are far beyond what the electronics inside can handle. Google "Counterfeit Fotek SSR" for details.[2] Since the failure modes are 1) fail in the ON state and 2) catch fire, this is not good for anything that draws significant current. The real ones are a lot more expensive than the fakes, and cost goes up with current rating.

[1] https://hackaday.com/2014/11/27/improving-the-t-962-reflow-o... [2] https://www.ul.com/node/81246