Amazon is currently running a lightning deal for IKONG Compatible Drum Unit for Brother DR420 for $10.39. It has a 20% off coupon to clip on the page. Clip it and it will bring the total to $7.39. If you choose no rush shipping, you get another $1 toward digital stuff.
It is compatible with Brother HL-2270DW HL-2280DW HL-2230 HL-2240D HL-2240, Brother MFC-7860DW MFC-7360N MFC-7460DN, Brother DCP-7065DN DCP-7060D, Intellifax-2840 Printers.