While there is only a slight difference in the base DPS of a Mk 10 to 11 or 11 to 12. That base is than modified by skills, consoles and power levels.

Example using big round numbers

Bse DPS x 3 Tac Consoles x 125 Weapons Power

100 x 78% x 4 = 712

110 x 78% x 4 = 783

120 x 78% x 4 = 854

As you can see your getting ~140 more DPS out of the extra 20 points, and I'm making some simple mistakes in the maths, because the consoles get Diminishing returns and I'm not factoring in skill points. I may even be making a mistake on the weapons power modifier.

Your cruiser is not ready for elites, by the way.

And I do have a one last question, what else are you going to spend the salvage on if not Weapons?