Not usually cheap, but there may be some bargains here:
Sportsman Gun Centre - Guns More
sadly not in my size or choice of clothing.
what is wrong with ex-military clothing when stalking? It certainly doesn't make you appear 'like a terrorist' who generally wear urban clothing to blend in...."
Their sales stuff is often small sizes which might work, but have a look at Jack Pyke clothing - very good value and then find a tailor or seamstress to alter it for hip comfort and inside length etc. Some of the women's tailored riding gear is good for under layers as well, but waterproof uppers are better from the usual hunting range.
It depends on how rough your terrain is on your clothing. Some of the surplus German and Austrian gear is plain green but very well made.