I just posted the quote below in another thread, I signed up just to point this out because I think many UK members here don't seem to be aware and are ordering their finasteride online needlessly.
... I've seen nobody else post this but in the UK it is possible to get a prescription for 5mg Finasteride which is non-branded & cheap.
I paid £5.99 for 28 pills from my local pharmacy (which quartered will tide me over for 4 months).
Was previously on Propecia for 2 months, paying ~£50 per month, so I was overjoyed with the saving. All I did was ask my pharmacist how much the 5mg would cost and then next time I saw my doctor I mentioned the massive price difference, asked if I could be prescribed that instead and cut up my pills. The doctor checked with a colleague but both were totally fine with it.
My advice to Brits is don't order finasteride off the internet, see your GP and ASK and it's highly likely you can get legit stuff cheaply from your local pharmacy.