I’ll admit to being a hobbyist on the technical side - I went through a couple of moderately expensive home roasting appliances, but I’ve settled on a $100 rotisserie toaster oven to which I added a $25 PID temperature controller. 18 minutes and I get a nice quarter-kilo of beans. I’m less of a coffee connoisseur - my beans all look the same color, even from batch to batch, and all taste decent - I can’t really drink Folgers anymore - but I can’t swear that James Hoffman would approve.
My green beans cost $15/kg, which, because there’s some mass loss during roasting, works out to ~ $18/kg roasted. Throw in a round $1 for electricity (1-1.5 kWh/kg). My local specialty roasters are all around $35-40/kg. 4* 20minutes = 1.3 hours, so I could notionally pay myself $14/hr and still break even. I could double the batch size if I were really concerned with time.
I am still, notionally, paying off those home-roasting appliances, though. They were convenient, but less reliable than the Walmart toaster oven.