I bought mine a little over a year ago, used it as a secondary printer till the starter cart ran out then refilled with generic bulk toner which worked fine.
To refill the starter cart, there are two screws on top to take out, then entire toner reservior comes off. Flip it over, take off 1 screw at each end of the then-visible metal+rubber strip. Dump in the toner and shake it down good, put the metal strip back on, wipe off any residual toner dust, and screw back onto rest of cart.
There is no need to buy a new cartridge and you may end up worse off buying a refurb cart if the refurb cart drum has bad spots on it. Based on ease of refill I suggest refilling till the original drum wears out (3 refills or so), then buying a new cartridge to get the new drum. Or, you could get the new cartridge earlier so you are refilling 3K pages worth of toner each time instead of 1K with the starter cart- as it's toner reservoir is actually smaller, they don't just ship it 1/3 full. It does not have a chip in it or a fuse.
... only down side is the 3000pg toner/drum unit is $80
'egg has it for $67 delivered