Maybe yes, maybe no. I can count on 7 shaves from the various Personna re-branded blades, like Pellas, and have gotten up to 10 from a modern Schick. So for me, cost per shave is not much greater than a DE.
On the other hand, I've seen others claim that they get only 3 or 4 shaves from the same kinds of injector blades, so you'll have to see how that works out for you.
Mm, true, I didn't consider the shaves-per-blade factor. If I can get 10 shaves per blade that makes it a lot more attractive cost-wise, yeah.