Yes most people think of meth as a drug, not the church. The .org.uk extention, partucularly the .org part I think goes very well with this domain - as there are lots of organizations to help meth addicts.
I do not know the going rate of .org.uk, but if I had to guess, I would say low $xx. I personally own meth.tv and only got reg fee appraisals, but I think the .org part of your domain makes it better.
Good luck!