That might be attractive to SpaceX, who currently has to trade off payload for the extra fuel required to soft land their boosters.
Nope, the opposite is true. If the economics of launch had to do with the price of fuel, SpaceX wouldn't have used propulsive landing in the first place. As Moonman62 said, the cost of fuel is a tiny fraction of a launch.
Last time I ran the numbers, and I'd enjoy a correction, Equatorial angular momentum adds 300 meters per second from launch over KSC/CCAFB. One reason SpaceX might not have hustled for that extra push is their dependency on federal funding.
Since SpaceX is way down at the bottom of the list when it comes to federal funding, not to mention that at least Boeing and LM are also on the list, the second part of that makes no sense. Equatorial launch makes it possible to get more into orbit with the same fuel.
SpaceX is doubtless scouting locations for suborbital service by the BFS, although getting a little bonus in the payload can't hurt as they take over the entire commercial lanuch business.
It's not the price of the fuel, it is the tradeoff of weight of fuel vs. payload weight into orbit. When you have to lift enough fuel to use for landing, that is weight you cannot lift as payload.
Delos D. Harriman would be proud.......................