Changes the price on

• Puts a new price on
• Changes the price of
• Changes prices, perhaps
• Marks sales prices
• Puts a sale sticker on, perhaps
• Marks up or down, say
• Puts a sale price on, maybe
• Labels again
• Puts a new price label on

Wiktionary Word definitions in Wiktionary
vb. (en-third-person singular of: retag )