The terms are "Affordable & Cheap" which vendors often use during marketing.
"Affordable" IMO means that a certain commodity may not be cheap but affordable depending on the financial class of the customer, While "Cheap" simply describes a commodity as affordable to everyone.
Have you ever been in a situation where you misinterpreted a marketer's advertisement that said "Affordable" and then you went ahead to assume it meant "Cheap" only to make inquiry and find out otherwise?
As others have said, cheap and affordable are very different things to very different people. To a billionaire a yacht is affordable but to most people it is so expensive it is unattainable. However cheap can be much more relatable to all people and used in similar contexts, like if the aforementioned two groups of people saw a 1oz gold bar going for $10 they would likely both say it is cheap - because that is a bargain price.