The Stingray in the original post was designed and built by Leo Fender, after he left Fender and started MusicMan. Leo left MusicMan some years later and started G&L after that.
MusicMan wandered in the wilderness for a while and ended up getting bought by Ernie Ball. They moved production to San Luis Obispo. The Ernie Ball instruments have been in the spirit of the original Leo instruments with a lot of evolution.
Part of the evolution was the development of the Sterling model, which is named after Ernie Ball's son Sterling, who runs the company now. The cool thing about being a God like Leo (or Ron W. for that matter) is that you can do anything you like and be revered. If you take over The Creator's company and screw with the slightest detail, you'll be chased through the streets with burning torches. So, EBMM was smart enough to launch an evolved instrument under a different name, rather than screw with the StingRay.
The Sterling has a smaller body and neck which is more contoured. It also has a coil-configuration switch for the pickup. They were pretty nice when they were launched, and haven't changed much.
The modern EBMM StingRays are pretty different than the original ones. They have a 6-bolt neck instead of 3 bolt and a much easier truss rod adjustment. The EBMMs have an oil finished neck instead of polyurethane (like on the bodies). The strings don't pass through the body anymore. And most StingRays have 3-band EQ instead of 2-band.
I bought a new StingRay in 1977 and it was my buddy for more than 15 years. I have to admit, it was not the best StingRay or the best bass I had. During the craziness of vintage instrument prices in the 90's I decided to sell it and got way too much money for it. I later bought an EBMM which is a much better bass with a stiffer neck and better construction, but not nearly as interesting as the original StingRay.
Are there cheaper MusicMans these days? They played around with an import line (SUB) for while, but I think that's gone now. Seems like every MusicMan I've seen for years now was $1500-2200.
David Fung