No it is not so. Pick one you like the most and make an offer with an 8 hour expiration time. If you do not hear back within that 8 hours, make an offer on your second home of choice, etc. If the second offer is accepted then you have a deal. If it is not and the first seller contacts you then you have the option of proceeding with that one. I think you should find a Realtor to work with you and guide you through the process.