You can buy all kind of production equipments such as: camera support, lighting, studio carts, grip, etc.
B&H has many manufacturers' full product lines, from highly popular brands to obscure, hard-to-find accessories.
ShareGrid is an online marketplace for sharing film and photography equipment with other people in your city.
The Camera Store
Full line dealers for the entire range of video production equipments, supplies, repairs and rentals.
Camera section of eBay. Facilitating online consumer-to-consumer and business-to-consumer sales.
GripUp is a London based filmmaking equipment store run by filmmakers. 5% discount for students.