seller's market vs market place

seller's market and market place both are nouns.

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

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

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

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

seller's market (noun)	market place (noun)
a market in which more people want to buy than want to sell	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