I bought some of the Salomon merino socks last year from TK, and they are excellent (£4-5 a time), and grabbed some more on my last trip to Bournemouth. The Trekmates stuff isn't fantastic, but I got a XXL drysack for a fiver, which looks pretty tough and big enough for a liner.
I did make a mistake when I bought a pair of gaiters - check that they are actually a matching pair. The two got tangled together, and although they looked identical, one is a lot shorter than the other. That's one of the problems with the place, a lot of the stock gets chucked about and mixed up.
Alas, my nearest TKMaxx is miles away, bit it does at least mean that I'm not tempted to buy even more kit.
Have a look at Outdoormagic's gear forum for a heads up on what in - they have a regular thread.