I had my comms capped at 50, so my choice was getting the BM saber, pulling mods, and immediately bought the WH saber. As a jedi, especially a sent, could then put the BM mods into another saber. Then you have WH main hand, and a BM off-hand. It increased DPS alot and took one of the major time consumers to achieve out of the picture right off the bat. As others have said, full BM takes no time at all, so might as well get a WH piece first. Some others like to get WH implants and ear piece initially. All up to preference really.