Credit farmers don't care much about rare drops ...
I am not sure if it still works anymore but, some of them used bunch of trial accounts for terminal mission. They had 1 lvl 90 char in group, rest were low level chars taking terminal mission (which were lvl 90 because of the one lvl 90 in group). All the low-lvls were placed in a vehicle following the lvl 90, who destroyed the lairs or what ever. After 10-15 they were rdy and started a new round.
Another way was by betraying SOE

... they created new accounts paid by credit card. They sold the newbie-rewards (AT-RT etc) and closing the credit card account

(safed the Credits on another chars). That was the reason why it was able to get AT-RTs on all well populated servers for 5mil.