I am working on a website where I need modules like Listing ([url removed, login to view]) and Classified Ads ([url removed, login to view] and [url removed, login to view]). Both these modules are not available for Drupal 7 and don't seem to be coming up anytime soon.
How much would it cost to build such modules for D7 and what would be the timeline? Would there be a cost difference if I share the modules with the community under my name?
I would like them to have them as standard modules so that going forward, they can be modified and upgraded with Drupal versions.