You can get a nice setup with a top end budget of $10K. With some do it yourself perhaps even a GC2.
I've tried friends Optishots, GC2s and Protees. To me, having both club and ball data can't be beat if one wants to improve on an actual course.

Of the swing sensors, that is Optishot, P3proswing and Protee, I would have to agree with sdak that Optishot is not as accurate as the other two. We take a high speed camera and place it 3 feet or so in front of the ball position. We use a rubber tee with the top of tee set at the height where the center of the ball should be. We of course could not compare exact swings, but the differences between the three is actually not all that different. They all seem to get the swing path about the same, at least for my swing. The main difference seems to be in ball impact on the face. We could not tell much difference between P3proswing and Protee, but Optishot would identify a ball stuck slightly on the heal or toe, I guessed about 1/4" to 3/8", as a center strike.

With the camera system setup right with Protee, it's an great system. Accurate and provides so much game improvement information.

P3proswing has come a long way over the last couple of years. It provides accurate club information, although the Optishot and the Protee sense my swing speed more accurately compared to my Trackman numbers. The Optishot was just a bit low and the Protee was right on my Trackman numbers. For my driver, P3proswing senses my swing speed about 3% to 4% low. This is not big issue since P3proswing provides a lot of club adjustments. One thing they have done in the last year or so is add ball information to their premium courses via a launch angle camera. This feature is great and makes the simulation much more realistic. This feature is a bit finicky, but overall works well. P3proswing has also changed the ball flight physics to more closely match that proven over the last few years by ball sensors such as trackman.

Good luck and play well