I'm assuming from your description it is a Uberti copy of an 1873 Winchester. Cimarron marketed a few 1892 copies in .45 Colt, but I don't recall Uberti making any 1892s.
Your gun was likely used in cowboy action competition, and most of these rifles have been "tuned" for the sport. Some are done by professionals, some by amateurs on kitchen tables. You will want to ensure that the rifle functions safely.
Best bet is to have a gunsmith inspect it and check the headspace. If that's not possible, make sure it cycles with the ammo you expect to use and that the lever safety (the little projection behind the trigger that gets depressed when the lever closes completely) is working properly...the hammer should not fall if the the lever is not completely closed. The rifle may have a "short-stroke" kit installed, which shortens the lever travel, and lever springs may have been modified; make sure the lever stays open when it's open and held vertically, and that the lever stays closed when held horizontally.
That's a very good price for a '73 in good working condition.