I think they are becoming more available all the time, their popularity has grown considerably in the last few years. There are at least 3 lfs in my area that have more than one species in stock at all times.
Hey jht what area u living in? There's a lfs in Urmston that's selling dwarf puffer now i think (went there a few days ago). U may want to check it out if u r interested!! They r sooo cute with those big eyes
May be a bit seasonal as well, when I see stock lists from our suppliers they don't always have an awful lot available. Sporadic availability, you could say.
I agree with Mountguppy. Most of the lfs don't really care about the condition of the tank. But the one in Urmston (west of Trafford centre) is quite good. The big chain pet store in Stockport (off A5145) is comparatively good as well. But that one doesn't sell puffers.