WHOLE CHARACTER
卖mài
to sell — to exchange things for money; to betray (卖国,卖友); to exert to the utmost (卖力,卖命); to show off (卖弄,倚老卖老)
卖 is to sell: 买卖 'business', 卖力 'give it your all', 出卖 'betray'.
ZDIC: 原为会意 — the traditional 賣 joined 出 'go out' with 買 'buy'. The simplified 卖 writes 十 over 买, a modern written shape rather than the historical pieces.
TOP: A WRITTEN CROSS PIECE (MODERN SIMPLIFICATION; THE OLD FORM HAD 出 HERE)
十shí
ten
Described structurally in 早; no invented story.
In 卖: top: a written cross piece (modern simplification; the old form had 出 here) Shown with its documented or clearly limited role.
BOTTOM: THE 'BUY' PIECE (SIMPLIFIED FROM 買)
买
Notice this part of the shape; it is not taught as a separate word in this lesson.
In 卖: bottom: the 'buy' piece (simplified from 買) 卖 is the flip side of 买: goods going out for money.