That would not work. Suppose Bob offers $1M for your house and you accept. 10 minutes later Charlie comes along and offers $1.2M. Why would Bob get out of that contract, when he knows that he can resell it to Charlie and make $200k minus the transfer tax (assuming you cannot reassign the contract). The only difference between allowing or disallowing reassignment is how many times the transfer tax is paid. Or if you're a sentimental seller and actually care about who buys your home.