The Stingray has a wider neck than the Sterling, similar to that of a P bass, so that may suit you better if you have larger hands. They come in a variety of different specs notably with either a 2 or 3 Band EQ (3 or 4 knobs!), and prices will vary depending on which one you choose (the 2 EQ cost more for some reason).They also come with a maple or rosewood neck. Sound wise the 3 EQ has more tone than that of the 2 EQ, but it really is marginal and not something you'd notice much when playing live, you'd not go wrong with either IMHO.
There is a cheaper made Stingray bass on the market confusingly also named the Stirling Sub, and I think these also offer similar tones, and are made outside the USA.
As to why SR's prices differ that would again depend on your spec, i.e any USA made model such as the 5 string, or the 2 EQ models (and the Stirling (USA) model, due to having a smaller body and slimmer Jazz type neck), will have a higher price band than a standard USA made 3 EQ Stingray.
Either way, whichever USA built Stingray you plump for, you'll not be disappointed with the build quality or range of sounds on offer. I've never played or owned a cheaper sub model so cannot comment on them. Good luck with your hunt.