Back when I did my research on where to get Avodart without prescription, this place seemed legit by what I read. Although do not take my word on it as I have never used it myself, my info is only gathered from what I've read. If you don't have a prescription you basically tick the box to have a doctor's consultation which costs 20 GBP and then they allow you to buy. Keep in mind that you will have to pay the 20 GBP consultation fee every single order, so might as well buy for at least 3 months if you.
Another option is go to Medical Wellness Center web site, pay $50 for consultation fee, and you can get a legit Avodart prescription to buy it either from them or other pharmacies in the states. If you're not from the states you could try use a redirecting shipping company to send you the Avodart to yours, not sure how well that would work with customs though.