Mnemonic

A gentleman dons a crown and sprints on his legs to sell goods at the bazaar. The crown dazzles every buyer — 'If royalty is selling it, it must be worth a fortune!' They empty their wallets for the crowned gentleman without a second thought.
Additional thoughts
Picture a distinguished man placing a golden crown on his head, then running through a market on tired legs, hawking wares. The crown is his sales gimmick — nobody can refuse buying from someone who looks like a king.
Quick recall
A gentleman in a crown races on his legs to sell royal wares.

Details

The keyword for 売 is sell. This kanji represents the act of exchanging goods or services for money, the fundamental commercial activity of offering something to a buyer. It encompasses all forms of selling, from small retail transactions to large-scale trade, and can also be used figuratively, as in "selling" one's name or reputation to gain recognition.
On'yomi
ばい
Kun'yomi
う.る、う.れる

Used in kanji