Unless you can spin on a wheel or buy one with some history behind it from someone who can demo that it works (and give you a spinning lesson)it's best to stay away from antique wheels. Why? Because these wheels may well have problems that are not readily apparent.
Know the history of an old wheel is nice, but it's seldom that any thing much is known about old wheels. Some old wheels have maker's names or marks, some have the initials of the original owner carved into them.
It's also highly suspect if someone purports to have a wheel used by a famous historical figure for sale (usually for really big bucks!). A year or two back, someone was selling a wheel on e0Bay - had it billed as Martha Washington's spinning wheel and claimed to have bought it from someone who had gotten it at a garage sale at Mt. Vernon. They said they had documentation on all of this but refused to show it to anyone but the buyer and then only after they had been paid for the wheel. Right!!!!
If you do know how to spin on a wheel. you can, on occasion find fairly good buys at antique shops. But if you spot one, be prepared to test it before buying. This requires being prepared with oil, a rag, drive band material, small pieces of wood to use to temporarily replace missing pegs or as shims, some sort of material to temporarily replace missing bearings (heavy cord will work in a pinch), a piece of rope to use as a temporary footman, and of course some fibers to spin. In other words, everything you need to make small repairs and get the wheel going. Most antique dealers will be happy to let you try to get the wheel going - after all, they may get a sale out of it

But don't count on them to know anything of the wheel's history beyond where they may have gotten it.
If you find an old wheel that needs repairs, there are some very excellent spinning wheel restorers out there and often they can tell you something about the wheel - an estimate of when it was made and where at the least. There are also some good books on the topic of antique wheels and an excellent publication called "The Spinning Wheel Sleuth".