GMT vs. SUB vs. YM

[SeaGoer]

I am looking at the list price diference between the GMT, SUB and YM at the TT and YG series and what I see doesnt make sense unless I am missing something.
.............TT...............YG
GMT......$7025..........$19750
SUB.......$7825..........$23100
YM........$8675..........$22550

The TT SUB is more expensive than the GMT most probably because of the depth rating and the TT YM is more expensive than the TT SUB probably because of the bezel. Kind of makes sense.

If we accept the above as correct then why the YG SUB is more expensive than the YG YM? Is it because of the extra links? The bezel of the TT SUB appears to be the same as the bezel of the YG SUB. The main differences between the YG SUB and YM are the bezel, the extra links and the depth rating. With the SS case, the price of the YM bezel shadowed the cumulative prices of the extra TT SUB links and the higher depth rating. This is not so with the YG series where the extra links and the depth rating with the 18k case (softer metal; more difficult to waterproof?) seem to take precedense.