The limited information we have is that SpaceX is significantly profitable (their fairing recovery, Raptor, BFR, and potentially even parts of the satellite constellation efforts are funded out of their profits). They have one production line and are launching 18 times per year. Their nearest competitor is ULA, with 3 product lines (Delta IV Heavy, Delta II, and Atlas V) and with half as many annual launches and with no capability to reuse. That implies SpaceX's margin can be far greater than their competitors, the opposite of your guess.

In rocket launch, your profitability is determined primarily by your launch rate and your number of product lines as there are a lot of fixed costs for maintaining launch pads and manufacturing lines. SpaceX is doing extremely well on both fronts.