Generally, you get what you pay for with toner. I've seen many copiers and printers get a fine coating of toner all over the inside of the machine when using aftermarket toner, and generally less solid print quality (I am a photocopier/laser printer service tech). Stick with the OEM stuff unless you don't care too much about print quality, or if you get the rated prints/cartridge for the machine.
HP printers are some of the most expensive to own on the market. That's not most expensive buy, but to own due to the cost of replacement supplies. They employ the Gillette razor theory of profit generation by selling the printer at an attractive price and selling the cartridges at a high price. Newer HP printers now have chips in the cartridges so the printer knows if there is a new or a refilled cartridge installed. A disturbing trend that will drive up the cost of refilled toner cartridges as the aftermarket companies have to replace the chip with something that will defeat the detection.
I personally favor Kyocera printers, and that is mostly due to my experience with servicing them. Higher cost of purchase (if you don't want to go to a factory dealer, lots to find on ebay or online) for these but the supplies are a lot lower. Kyocera has a way to compare the total cost of ownership (TCO) on their website between different makes of printers by clicking on TCO Tracker on
this link.
I use a Kyocera FS-1700. It's a 7 year old model that I bought off of ebay from somebody that aquired several from when they came off of a business lease. Mine was nice, cleaned up and in great condition with a newly refilled toner cartridge for $125. I've seen new models on ebay (like the FS-1010) for under $500.