One good thing about toner is that it doesn't dry out fast, like ink. I have cartridges that have been in place for two years and work fine.
You are correct in your assessment of the cost per sheet. The larger the cartridge the cheaper cost per page.
One thing you may want to research is weather or not generic toner cartridges will work or not.
If a color laser printer is priced at $149 then it probably doesn't come with cartridges at all or just starter cartridges. Not the 2000 page capacity. Probably more like 100 page.
If you belong to Sam's Club or Costco, look at their printers. I am not sure if things are still the same but when I bought my 2300DL it came with all the cartridges, drum, etc. They were the larger capacity too. The price to buy all those at that time was only $100 less than what I paid for the printer.
The only compliant I could make about my 2300 is that it is noisy.
One thing about HP is they don't support their products for very long. So one or two generations later of Windows they probably won't release any new drivers and won't even host previously released drivers.