Look at it this way, modifications use less resources to craft than offhands. Get your hilt/barrel/mod/enhance recipes all purpled out and sell those.

Unfortunately this is incorrect, they take twice as many purple mats to craft as offhands do and they sell for essentially the same amount. The only difference is when you crit (on hilts anyway) you'll make ~25% more selling 2 than selling 1 augmented offhand.