Mate I always buy straight from NTBM with a discount code that takes care of the P&P then you just gotta see if HMRC decide to charge you. I get charged about 4 times outa 10 but it's never much more than £20.
Admittedly you gotta buy a load at one time but $150 is around £95 at the moment and you get plenty more than a couple o' bottles of unleashed.