Remember that under the Homeland Security Act, retailers are not permitted to put Black Powder out on shelves where the public can see and "touch" the containers. You have to ASK the store personnel- and often only the Manager actually knows the answer- if they have Black Powder. It has to be stored in a back room in an approved Safe. If you have a Cabelas, or one of the other Big Chain Sporting goods stores around you, most likely they have black powder.
Having said that, buying it on line is cheaper, even when you have to pay a Hazardous Materials fee for the shipment.
On the index page to this forum, up top, you will find a box marked " Member Resources". Towards the bottom of that box is a thread marked, " Articles, Charts, and Links." If you click on Links, it takes you eventually to a list of suppliers, including distributors of Black Powder. Click on those names, and you get their websites, and usually, current price lists. If not, a phone number is always given- often toll-free- for you to call for current prices, etc. Powder Inc will sell you as little as 5 lbs. with some discount over what you will pay for it retail back home. The smart thing to do is get together with other BP shooters, pool your money and order a 25 lb.( Or 50 lbs- the maximum you can have shipped to you in one order) case together, so you get the maximum savings. These companies often have other powders they sell cheaper than Goex- store "brands"-- so don't hesitate to ask about them. And, some companies have powder they sell in bulk form-- you supply the 1-lb. containers. The bulk powders are usually the cheapest. Right now, a case of Goex powder from Powder, Inc. is costing about 16 dollars a pound, delivered to your door. That includes the cost of the powder , the shipping costs, and the haz mat fees.