[Grammar] – Is the phrase “at the cheapest price” able to abbreviate to “the cheapest”?

Is the phrase “at the cheapest price” able to abbreviate to “the cheapest”?

Hi, I’m confused to read the following sentences; Where can I get this the cheapest?

I presume that the sentence is the same pattern as the sentence of “Let me explain it really quick.”
I mean, you can say “Where can I get this the cheapest?” regarding colloquial English.
That’s because the word “cheap” can be used as adverb as well as adjective.

But somebody explained to me that the cheapest is the abbreviation of the phrase “at the cheapest price”.
But I feel that the explanation isn’t quite convincing.

Do you happen to say the cheapest instead of at the cheapest price?

Thank you in advance.