Good morning and welcome.
Posing the question of whether or not to buy a Kawasaki sled to a Kawasaki sled forum sounds like it might be rhetorical.
From what you describe the sled sounds well worth the investment. But don't be overly optimistic. Good spark and good compression do not mean that you won't have your work cut out for you. Probably everyone on this forum will say something to the effect of "if you don't know the full history of the sled that you will need to pull it apart, check everything and replace critical components like crank seals and carb boots."
Sounds like a great find. Good luck and feel free to bring your questions to the forum. And, if you need a manual, send me a PM.