What is Cheap ?
Cheap is (adj) which does not cost a lot of money If you want a cheap radio you ought to shop around. Why do you go by bus? – Because it’s cheaper than the train. Buses are by far the cheapest way to travel. (adv) at a low price I bought them cheap in the local market.(noun) on the cheap in the cheapest possible way We got these chairs on the cheap in an auction.
source: Easier English, Student Dictionary Upper Intermediate Level