actually there are several top name producers that actually product biodynamic wine. there are certain criterion that makes a wine certified as biodynamic from the official international biodynamic body. some producers don't bother apply for the certificate but practice it anyway.
sometimes they will say it on the bottle, but usually this kind of info it's mentioned in their website or back of the bottle or some press release.
it doesn't make it more expensive as quite a number (but not majority) of producers are doing it already. Keep in mind, there are differences between biodynamic, organic and natural wines.