1. Make Joomla menu links to VirtueMart for registered access only, especially the link to VirtueMart Home Page.

    • you can leave a public link to VirtueMart Account Maintenance if you want to provide a registration form for wholesalers and set Joomla's user manager to require admin approval for registration
    • or publish the Joomla login module if you want to manually create users.
  2. VirtueMart modules such as search and category menu can be set to display only to registered logged in users.
  3. You can add another step and make the products only displayed for the wholesale shopper group.
  4. Also enable in the VirtueMart config "enable checkout only for registered".