Yes, STANDEES is a Scrabble word!

Letter values in Scrabble US: S 1, T 1, A 1, N 1, D 2, E 1, E 1, S 1.

Is it a valid word?

STANDEES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

someone who stands in a place where one might otherwise sit (as a spectator who uses standing room in a theater or a passenger on a crowded bus or train)
a lifesize cardboard cutout (usually of a celebrity)