They're pretty expensive up front. I bought a low-ish end one for about $130. I expect you can pay a lot more, but you wouldn't want to pay much less. But compared to constantly buying expensive blade refills, it's definitely cheaper.
I was just talking to a hirsute friend who claims to have killed two electric shavers with his beard. That may be one reason.
But basically - I don't know. For me, it's better in every way, including cost.