Meritline offers the Merax Brother TN450 Compatible High-Yield Toner Cartridge 2-Pack for $33.95. (Select the 2-pack option to see this price.) Coupon code "MLCE27XN" cuts it to $21.95. With free shipping, that's $10.98/cartridge, tied with our September mention, and the lowest total price we've seen. (It's also the lowest we could find by $2, outside of the price below.)
A close price: E-auctions-express via eBay offers these cartridges for $22.95, also with free shipping.