You mean "ANSI/ABMA Grade 3". ABEC, RBEC and Class apply to ball bearings and straight roller, spherical roller and needle bearings, most of which are not separable into inner and outer parts.
And although I won't argue that the odds today of Grade 2 Timken parts actually meeting Grade 3 are pretty good, they don't have to. The only way to find out if the factory was having a bad hair day is to buy them, install them, and check runout. Plus Timken has had some trouble in recent years with Chinese counterfeiters. Before I bought anything through Amazon, I would figure out the real name of the actual seller and do some research.
My wife has bought some things off of Amazon.com that as far as I could tell were actually sold by Amazon. However, everything that I have ever bought (from various books to motor controllers) came from and were shipped by a third party. The latter case is what I was referring to.
Price around got mine out of Cal. a couple years ago for around $200 shipped, the one cup is the pricey one. Some one after i did mine did one with a standard cup, don't remember how. Also you don't need precision bearings.
Those prices are for ABEC Precision Class 3. You don't need precision class 3 bearings for these lathes. ABEC Standard are of sufficient quality and precision to meet the precision capabilities of these lathes.
Prices quoted on Amazon.com less than 10 minutes ago as of this writing. Lower prices may be available, you have to do some digging to find them.
Those cups have a stepped rim and are not demanded in large volume, hence the high prices for the cups.