movement in o/s drive shaft 52 reg m3 convertible

[BRI105]

could do with a touch of help please. theres about 1/2" movement on my o/s drive shaft when i was looking at it today. i don't know much about mechanics but i'mpretty sure this isn't normal. is this a comon problem? and does anyone know roughly how much to fix it? any help is much appreicated