commerce vs buy in

commerce is a noun but buy in is not a noun.

Word	Noun	Adjective	Verb	Adverb
commerce	Yes	No	No	No
buy in	No	No	Yes	No

commerce (noun)	buy in (noun)
transactions (sales and purchases) having the objective of supplying commodities (goods and services)
social exchange, especially of opinions, attitudes, etc.

commerce (verb)	buy in (verb)
	amass so as to keep for future use or sale or for a particular occasion or use