My wife suffers from Coeliac disease and to be honest, the few times we've had the prescription stuff (to try it) it's been downright terrible anyway.
Yes, gluten free food in supermarkets and other shops cost more than "regular" counterparts (not least due to the idiotic fad surrounding going "gluten free", trust me, if she could, she'd eat gluten), but the Genuis/Warburtons/Schar etc brands taste 100% better than the junk you get on prescription.
Should have been ditched years ago, sure there might have been call for it 5-10 years ago, when gluten free product choice was both rare and limited, but recently things have been vastly improved (the one upside to the "healthkick fad").