I tend to only buy physical anime and manga for series I particularly love - feel like I should give a little back since the UK market doesn't get much to start with. I have zero interest in merchandise though.....was tempted by a Nyanko-sensei plushie in Akihabara but it was fecking massive and I didn't have room. Aside from that moment of "OMG WANT!" I've no real interest, just pick up small things like the odd pin or keyring.
Love looking at artbooks, but they are so expensive I can never justify buying them.