I buy coconut oil, almond and coconut flours from realfoodsource (.co.uk)
Google Nak'd's own website (can't remember just now what it is) - they often have some really good offers on boxes of bars and do some good variety packs too.
As for meat - I have a fairly local butcher that stocks only locally produced, grass fed produced so use that exclusively. It is, granted, more expensive than a normal butcher, but cheaper cuts are easier to get. Primal Britain's website has a good resource section if you're looking to see if there are any good suppliers near you.
I'm lucky (in some ways) in that I've only myself to feed so can pretty much set my own budget. Must be hard trying to eat well on a tight budget. Good luck.