The main advantages of a trash bag frame over a trash can are lower weight, lower price and collapsibility. These characteristics make a trash bag frame easier to manipulate and store than a similarly sized trash can.
The folding trash bag stand, available at the e-shop of Harbor Freight Tools, is a trash bag frame. It holds trash bags of up to 33 gallons, its shipping weight is 4.50 pounds, and its usual price, as of 2015, is under $10.
The Rubbermaid 32-gallon garbage can, which Lowe's offers on its site, weighs 9.97 pounds, and its price is between $25 and $30.