If you want vqmod version you will need to pay 20$ plus.
Help with installation is free but you must send me admin access to your site
Users can add separate products in admin. They can edit , copy , view , delete only their products .You can set up for which user group this will work.All others groups can work with products normally.
All products and orders from all vendors are visible for admin
Vendor user can see only his products and orders.
Vendor user can see only his returns and reviews
Vendor user can see only his products and orders statistic.
for vendor use username demo password demo
for admin use username admin password admin
Go to admin->System->User Group , select group that will have separate products and press Edit , and for Separate products(vendor) select Yes.
Go to admin->System->Settings , select your store and press Edit. Press tab Options. Under Vendor Settings you can select what user can add/edit.
They can have :
User can add/edit his categories
User can add/edit his manufacturers
User can add/edit his information pages
User will have separate attributes
User will have separate options
User will have separate downloads
User will have separate filters
Link to ordered products sale->order product