http://www1.us.dell.com/content/products/category.aspx/printer?c=us&cs=19&l=en&s=dhsYou might also try a major refilller such as Davis Inkjet (
http://www.davisinkjet.com/locations.htm, multiple locations) to see if they can do anything with your cartridges.
Although Office Max / Depot advertise they recycle Dell toner cartridges, neither SELLS Dell or compatible. That's one problem with the fragmentation of the printer market: With thousands of models from dozens of brands, it may be difficult to source some of the less common models. (I'm not saying these are all functionally distinct, but the contemporary standard is to pair circuitry in the printer with a chip in the cartridge that prevents use of 3rd party, or even refilled, cartridges.)
A columnist just this week commented (tongue in cheek, I hope) that with promotions the way they are, it could be cheaper to buy a new printer than to replenish the supplies. With low-end color lasers (which have more pieces to replace than just a complete toner cartridge), the cost of all the consumables adds up to a significant percentage of the new price. Although that argues against performing major repairs, you still buy toner because consumables don't all run out at the same time and you'd be throwing away considerable potential capacity.