We recommend that you buy Genuine (non-3rd party) toner from Staples (20% Rewards) or Office Depot (25% Rewards). This would be the most straight-forward option. 

You can also buy direct from the manufacturer but you probably won't find it any cheaper than you would at Staples or Office Depot. The cost of Genuine printer ink and toner is hard-set by the manufacturer.

Unless you print a lot of documents, we also recommend buying the standard cartridges instead of the XL cartridges they sell, but that's up to you.