wordpress template modification

wordpress template modification: the template i would like to have some work done on, is by [login to view URL], the template name is realtorpress. the realtorpress template allows users to submit or list a property on a website free or paid, depending on the selected package. the option to list a property is limited to one property, one payment. i would like to include the option to list multiple properties for one payment, a credit system. the user (listing the properties) must select between 1, 5, 10, 25 properties which he/she gets as a (one) credit. one credit per property listed. the credit cannot be re-used if the property listing is deleted within the expiry time. the credits used and available together with a date expiry entry, must be viewable in the 'manage property' page, were the user can manage the property listing(s). the 'manage property' page is part of the default template. the credits used (for properties listed) must expire after 6 months. remaining credits must expire after 12 months. i can provide the theme files together with a license key. i also have a domain, some space on a webserver with a mysql database available if needed and logins. [login to view URL] is currently updating the realtorpress template and should have a new version in march, but without the functionality that i am looking for.