If you were in the US my answer would be - absolutely. Get a few of their sampler packs (actually the one with the Ingenuitea is great). But then again if I were in the UK having to pay international shipping I might think of a local option.
BUT! You are paying British Pounds for US Dollars. So everything at a US Site is a steal for you. So I'd say go for it.
I got their black tea sampler and I've been very happy with the selection. Their English Breakfast tea has a nice smokey tone I've not tasted w/ other English Breakfast teas and I find it quite pleasant.
Once you get hooked there's no turning back, before you know it you'll be hunting down specific years and makers of pu ehr.