It also depends on how effective they are. If they do a great job growing corals and have a pretty decent PAR and longevity then they would be worth paying double the price of a t8 bulb.
im not sure where i read it.. but that Coral Reef Shop in burlington carry these orphek LEDs and there whole store is exclusivly lit by them. a whole wall of tanks is lit by these LED tubes.. he talks about par readings also somewhere in the thread. maybe on aquarium pros or canreef but its a pretty cool led.. and they look good.