Surprisingly I've found the best prices for gas canisters are often either commercial campsite shops (although some of them are certainly where to find the highest prices too, so it's pot luck) and cluttered backstreet hardware stores. Can't point you to particular ones, I'm afraid, but it's well worth popping your head round the door if you happen to spot one.
As far as cookware goes, try to avoid tall and narrow pots unless you're just going to be boiling water. Unless I'm hiking and really need to reduce the weight and bulk I tend to use a cheap billy can, popular with bushcraft types and fairly easy to find (or fit a wire bail onto a simple pot). If you've just got one burner then more than one pan might not make sense and a billy style (or something like the MSR kettle) will be easier to pack, lighter and mean less washing up 
