If you went to the bank and took out $20, then gave it to yourself, would the bank give you a round of applause?
If you painted an awesome picture, then put a $20 price tag on it, then used the $20 bill you took from the bank to purchase your own art, would people applaud you? :)
But what if I pay 20$ for my picture to get to a huge gallery and get recognition from a lot of people who will then auction it starting from 20$ price? :D
Then you're stepping into the world and business model that helped create the starving artist.
The only thing about that gallery is that you get what you have paid for it back. So you get a free marketing and also a couple more customers.
You get that for free here with each post.