How do I sell my equipment for a better price?

I know that th trading skill increases the % of item's worth you can get in credits, but is there any other way to get more for a piece of equipment?

Increasing trading skill is main way for a better price. But also you can increase a base price of items by upgrading them with certain types of micro-modules.

Third level:

• Platinos. Cost +20%. All equipment.
• Gogaal. Cost +25%. Gaalian only.

Second level:

• Stoplay. Cost +50%. Not for weapons or hulls.
• Impalegun. Cost +25%. For scanners only.
• Paragon. Cost +20%. Peleng grippers only.
• Maform. Cost +60%. Maloq weapons only.
• Jumpgator 3.11. Cost +40%. For engines only.
• Extremer. Cost +60%. Maloq hulls only.

First level:

• Likebaanite. Cost +150%. Gaalian only.
• Broing. Cost +40%. Peleng hulls and protection generators only.

I recommend you to use only Likebaanite and Platinos for selling items because this two micro-modules have no other bonuses.