Offer database

I am looking for someone to write a program for me that allows real estate agents to upload an offer to a platform and it automatically emails it to the seller and myself at the same time. Of course, this program would have to have a database that holds all my listing address and that sellers email address. I would have to maintain the database or back end and add as I get new listings. Is this something you can do? Any idea what something like this would cost?