Hi-- There are a bunch of places online to get brewing supplies. Northernbrewer, ECKraus, etc. But if you have a LHBS near you you really don't need to.
Your local store should have yeast energizer and yeast nutrient, either seperately or as a mixed powder blend. You don't need mead yeast... You can use champagne yeast, wine yeast, or even ale yeast. I always use D47 wine yeast. A friend of mine always uses champagne yeast.
I guess what I'm saying is you don't really have to buy "mead" yeast or "mead" nutrients, etc. Hell--you can even make mead using bread yeast from a grocery store. For nutrient--you can use raisins.
If you prefer to buy mead specific products--You might just do a google search for brewing supplies and then shop for the best prices.
Honey can get very expensive unless you find a cheap source from a bee keeper or similar source. I and many others I know can make great meads using jugs bought from GFS. Runs about $40 for 18lbs. Never had a problem with it. Good luck to you!