buyer's market vs market place

buyer's market and market place both are nouns.

Word	Noun	Adjective	Verb	Adverb
buyer's market	Yes	No	No	No
market place	Yes	No	No	No

As nouns, market place is a hypernym of buyer's market; that is, market place is a word with a broader meaning than buyer's market:

buyer's market: a market in which more people want to sell than want to buy
market place: the world of commercial activity where goods and services are bought and sold

Other hypernyms of buyer's market include market, marketplace.

buyer's market (noun)	market place (noun)
a market in which more people want to sell than want to buy	the world of commercial activity where goods and services are bought and sold
	an area in a town where a public mercantile establishment is set up