Generally equivalent pieces should have the same sale price regardless of who sells it.
Most galleries will have their artists sign a contract. These contracts almost always include a statement about pricing outside of the gallery.
So a bowl you sell for $200 the gallery would sell for $200. Remember it always costs you something to sell a bowl yourself. If it is in a show you have your time, the booth fee costs, entry fee, booth setup, transportation, credit card processing costs, etc etc
Sometimes there is wiggle room
One gallery(now out of business) that we had a clause in the contract that said we could not undersell the gallery.
The gallery wanted my Christmas Ornaments which I was selling for $50 we worked it out that they would sell them for $60 and I would sell them for $50 and they would get 10 to sell.