trade down

verb

1. (intr, adverb) to sell a large or relatively expensive house, car, etc, and replace it with a smaller or less expensive one

Idioms and Phrases

Exchange for something of lower value or price, as in They bought a smaller boat, trading down for the sake of economy. Similarly, trade up means “make an exchange for something of higher value or price,” as in They traded up to a larger house. [First half of 1900s]