It's not about what you sell, it's about how much gets paid to your crew. Still works at the same rate of 1 arx/million paid to crew for me.Seems that selling high valuables in smaller batches been nerfed.
Did 4 jumps, docked, sold 324t of LTD in 18x 18t batches (20 something millions per transaction) then relogged.
11 arx, 1 being for exploration.
It used to arx waaaay more than that.