$13.31 Per Half-Move

We don't see many signed scoresheets here on Top eBay Chess Items by Price. One reason is that I don't find many scoresheets that are worth three figures. Another is that they aren't particularly appealing visually. A few years ago we had Mystery Capablanca Letter (July 2015), which was a scoresheet in the context of a letter. Some time before that we had The Great Pretenders (April 2012), from the 1974 Karpov - Polugaevsky candidates match. The item pictured below was titled 'USSR Chess 1975 year score-sheet Karpov Tal TOURNAMENT Russia Spartakiada'. It sold for US $479, 'Buy It Now'.

The description said,

The courses of party are written down by Karpov's hand. RARE Russia soviet greatest Russia Chess 1975 year form scoresheet autograph signed by Anatoly Karpov and Michail Tal. 100% original scoresheet of Chess USSR Tournament played in 1975 year, from the game Karpov - Tal, played in July 23, 1975.

For 'courses of party', read 'moves of the game'. The rest of the paragraph is self-explanatory, although the game was Tal - Karpov, rather than Karpov - Tal. I suppose the scoresheet headers, written in red, were prepared by an arbiter before the game. Next to the players' names are the teams they represented: Latvia and Leningrad. Karpov's signature (at the bottom of the Wh!te column) matches an autograph on a book I own, mentioned in Two More Autographs (June 2016).

For the complete game, see Mikhail Tal vs Anatoly Karpov; Riga ch-Latvia (1975) on Chessgames.com, although I'll go with the item seller's mention of 'Spartakiad', rather than Chessgames.com's 'Riga ch-Latvia'. The game lasted only 18 moves, thereby valuing the scoresheet at nearly $27 per move (or exactly $13.31 per half-move).