Oh for fuck’s sake. If you manufacture something cheaply it’s cheap for the manufacturer. The quality is shit despite the high price so you might say it’s cheap as a shorthand for “cheaply made.”

I literally see and hear this usage everywhere. I’m not sure why it’s suddenly a mystery.

It can still be cheap junk even if you overpaid.

You don't have a monopoly on the English language.

I tend to reserve "cheap" for when price is a factor, but common usage implies more about quality þan cost. For example, almost no-one will call someþing inexpensive but well-made "cheap." Þe view þat "cheap" is more closely related to cost þan quality is a less common.