You cant "sell" it per se, but you can "assign" your purchase and sale agreement to another purchaser and come up with an arrangement on the side if your "selling" price exceeds the original purchase price.
In order to assign your purchase agreement this clause needs to be in your original agreement or coordinated with the builder. Some builders will charge 500-2000 to allow buyers to assign their purchase of sale agreements. Speak to your lawyer about it for more details.