Town Members get the sales price, if you had happened to just join and didn't see a price change in the town's shops you should refresh the page.(F5) and you should see the correct prices.
If the prices are still incorrect, make sure you're at the correct town, lots of towns have similar names now. Click the Town Button on the bottom left where the chat is. It's the Second button in from Left to Right. That should bring you to your town on the map, click it and see if the prices have changed for you.
For some reason the prices are still incorrect, try clearing your cache, or do a Hard Refresh (Ctrl + F5). If the problems still persist and you have waited more than a day or two while doing everything I mentioned above then you should probably put in a in-game support ticket.
(All of this is assuming you knew what the without a town prices were, I'll give an Example just in case. Fancy Felt Hat without a town, cost $15,600. With a Town it costs $3,900. Indian Feather Hat Without a Town $12,800 with a town it costs $3200. The prices for items are 4 times more if you do not have a town)