cheapness vs bargain rate

cheapness and bargain rate both are nouns.

Word	Noun	Adjective	Verb	Adverb
cheapness	Yes	No	No	No
bargain rate	Yes	No	No	No

As nouns, cheapness and bargain rate are synonyms defined as:

Other synonyms of cheapness include cut price, cut rate.

cheapness (noun)	bargain rate (noun)
a price below the standard price	a price below the standard price
tastelessness by virtue of being cheap and vulgar