A couple years ago my consumer grade b/w laser printer died after five years of rather infrequent use. I decided I'd rather just take a USB stick to commercial printers than ever shell out for some consumer grade piece of crap again. Might a modern dotmatrix be cheap and super reliable? Like, I can buy it and plan on it working for the next 20 years?
Operating costs are relatively low but they are definitely NOT cheap to purchase.
I used to work as a service rep at an airline. We used these things extensively for printing airline tickets. These tickets had four red carbon-copy type pages that needed to be printed at once, and a dot-matrix printer is the only thing that handeled this well. It was a small office and we had just a rickety old Star Gemini II printer, but I must have printed thousands of tickets with it before it was decomissioned when e-tickets made their entrance.