What's the cheapest to operate (per copy) 4-in-1 printer, preferrably laser printer?

I'm currently using a Samsung 4-in-1. An original cartridge costs 4K (I believe most laser printer cartridges cost the same). I use those cheap toner refills, but after a while, the printouts will develop lines and becomes grayish.

I'm thinking of those inkjet printers hooked with continuous ink, but I think the printing speed of inkjets can't match laser printers.