300% Mark Up!?

I read this today from a guy who claims to have been a floral wholesaler. Can anyone comment on whether this sounds right?

"I used to be in the wholesale flower business, so I can tell you some of the dark secrets. Florist's usually operate on a three hundred percent mark up! There is nothing wrong with that, most florists are struggling to cover their over heads!"
From Helium.com

Obviously, we pay florists for their skill, creativity and time. But 300%!?