It literally is.

"Verb

"purchase (third-person singular simple present purchases, present participle purchasing, simple past and past participle purchased)

"To buy, obtain by payment of a price in money or its equivalent."

https://en.wiktionary.org/wiki/purchase

"Verb

"buy (third-person singular simple present buys, present participle buying, simple past bought, past participle bought or (archaic, rare, dialectal) boughten)

"(transitive, ditransitive) To obtain (something) in exchange for money or goods."

https://en.wiktionary.org/wiki/buy#English