Learn how to haggle
Most pricing can be bargained unless the store is clearly labeled as a fixed-price retailer. Not just for souk items; taxi costs, riads, dinners, tour prices, and the lovely leather goods on display may all be negotiated. People treat you as though you've just stepped off a plane and are a bumbling tourist who's a walking ATM. Prove them incorrect, then! It's unfortunate, but it's the norm in Morocco, and if you don't haggle, you could find up spending 10 times the normal price.
You shouldn't feel guilty about haggling; it's expected, and it can be a lot of fun. Knowing that you have nothing to lose by not purchasing the item is the art of haggling. Maintaining your cool. Having a price limit in your mind and not exceeding it. If they refuse to negotiate, go away and wait for them to counter with a reasonable price. If you don't receive the price you desire, remember that there are other stalls selling the same thing.