stamp dealer vs bargainer

stamp dealer and bargainer both are nouns.

Word	Noun	Adjective	Verb	Adverb
stamp dealer	Yes	No	No	No
bargainer	Yes	No	No	No

As nouns, bargainer is a hypernym of stamp dealer; that is, bargainer is a word with a broader meaning than stamp dealer:

stamp dealer: a dealer in stamps (whose customers are stamp collectors)
bargainer: someone who purchases and maintains an inventory of goods to be sold

Other hypernyms of stamp dealer include dealer, monger, trader.

stamp dealer (noun)	bargainer (noun)
a dealer in stamps (whose customers are stamp collectors)	someone who purchases and maintains an inventory of goods to be sold
	negotiator of the terms of a transaction