Dictionaries are helpful, but in speech we put words in context.

If my music stand fall apart, I might say it is a cheap piece of junk. Here,the stand is what's cheap.

If I buy a fine guitar for $50, then the guitar was cheap, but it is not a piece of junk. The price, not the guitar, was cheap.
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One of the problems of English for learners is that we use simple words to mean many things. Take ""get."

I get this thread - understand it.

I'll get a loaf of bread - obtain it.

To get the flu - be infected

You're gonna get it! - be punished

Get out! - leave

and recently, Get out! has come to mean "I don't believe you."
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As for "gotten", if you are not aware that American speech preserves old forms, then you haven't done much reading about the English language.