the colorimeter to get in the sub-$200 range is the i1 display 2 (lt variant comes with netured software and lower price point, but the packaged software is only useful for PC calibration).
Pair that with software from either calman(added expense but user friendly) or HCFR (free but steep learning curve), and your service menu and you'll be able to get a very accurate greyscale and be able to more precisely set your white level, black level and to adjust both your color and tint.
The biggest get will be the white point and greyscale, it's hard to deffine "worth it" my wife doesn't think my time spent playing with the TV is worth it. And that's just my free time after she goes to sleep. Personally I'm ready to take another pass at it tonight after she goes to sleep. Quantifing perceptual difference is hard to do. At least you can use it to calibrate your PC too.
white point: cie location and color temprature of white
white level: lumanace of white
black level: luamance of black
grey scale: the tracking of grey staing at the same point as white as the lumance is reduced
color and tint controls do different things based on different set designs.
CalMAN Lead Developer