Rowling (J.K.).- Tiffany (John) and Jack Thorne. Harry Potter and the Cursed Child, first edition, sixteenth impression, signed by J.K. Rowling, Tiffany and Thorne, 2016.

£1,000 · At auction with Forum Auctions

Rowling (J.K.).- Tiffany (John) and Jack Thorne. Harry Potter and the Cursed Child, first edition, sixteenth impression, signed by J.K. Rowling, Tiffany and Thorne on title, Rowling's holographic sticker on half-title verso, original boards, gilt, spine head slightly bumped, dust-jacket, upper and lower panels fractionally creased at head, overall near-fine, [Errington B22(a)], 8vo, 2016.

Found via Rare Books Intel, a search across rare-book dealers, auction houses and marketplaces worldwide.