We use shared episerver database, blob storage and Find index in development.
Some developers prefer to use localhost, and others prefer to set up dev.mystite.com in the hosts file.
Can Find be configured to ignore domains? Some pages are indexed twice (one document per domain), so we have to re-index everything from time to time.
Have you tried using the same main domain (the URL property in CMS Admin manage website) and then just adding localhost as an additional hostname?
make sure that there is not any Primary type Hostname for the SiteSettings (Config tab -> Manage Websites)