Which one has most revenue potential, though? SpaceX makes medium-heavy rockets, and will soon make a super-heavy. This means that their primary competition is the Ariane 5 (especially once they have their super-heavy, which will allow them to compete in the heavy GTO market). Ariane 5 is currently on about 5 launches a year costing 140m euro a shot, and SpaceX plans to undercut it. Let's say they take the whole Ariane 5 market, and also the whole commercial Proton market. That's probably about a billion a year, in a fairly low-profit market.

Of course, they also make some money on NASA contracting and grants, but I don't think anyone has ever managed a huge valuation on being a government contractor.

It's entirely possible that SpaceX will open up whole new fields of space industry, but at this point it's hardly something that most people are going to bet on.