Mush Shops are a more efficient way or selling than with a regular store permit?

If you pay your own bills, mush stores for 2 weeks, I would think uses a fair amount less electricity than a computer on for 2 weeks, and its a lot easier too :p

2 weeks is probably worth it too, but I don't really need 2 weeks to sell everything I have. 1 week long shop every month or two is enough for me.