I personally by Amateur Photographer(affordable with upto date articles, and being aimed at amateurs not too intimidating for me, lol) and occasional Photography Monthly.
Occasionly I buy random ones if an article or feature catches my eye, but those are the main ones I buy.
I'm not very keen on the magazines specifically aimed just at digital but that's just me personally.
No harm in buying old magazines at all I'd say, every bit as useful and more affordable!! The only downside is not getting so much up to date info and reviews etc..