The process of a customer purchasing a higher quality product than originally planned, several products instead of one, or more of the same product
adding a higher-priced, higher-quality version of a product to the range, generally to increase sales of the lower-priced model through consumer association of its image with the more prestigious model See Trading Down
If someone trades up, they sell something such as their car or their house and buy a more expensive one. Mini-car owners are trading up to `real' cars Homeowners will feel more comfortable and they may feel ready to trade up