Yes you need a prescription, but alot of people get around prescriptions via the internet....not sure if it's legal...but.
The cost was ALOT! If I'm not mistaken, I thought it was like $185 (I could be wrong....I can't really remember, I just know it was not cheap), so I didn't get it until my insurances deductable was met (otherwise I would have had to pay for it).
The tube lasts FOREVER though, I've had this tube for 5 or 6 months now and it's not even half gone. You use soooo little (a pea size). This one is pretty strong though (stronger than differin, and strong for me w/sensitive skin), and has to be gradually worked up to use it every day. I think at first it was 2 x a week, then 3 x a week, then 4 x a week or something like that....it was VERY gradual in working up to it every day. Oh and you use it at night. I still have to mix it with my moisturizer, cuz I can't just use it alone....