Bike snobs don't like kickstands, except for maybe on dedicated touring or city bikes.
They are not too expensive, though. As mentioned above, be careful if getting one that clamps on a frame tube - it can damage a lightweight frame. If the dropouts on the frame are flat you can get one that is held in place by the rear axle. This can be a bit of a nuisance on a QR wheel but it definitely won't damage the frame.