Excellent vintage tenor banjos are dirt cheap right now. A few brands to look at:
Paramount, Bacon, B&D (Bacon & Day Silver Bell, Senorita, etc), Vega, Oriole (made by Gibson), Buckeye (made by Gibson), Kalamazoo (made by Gibson), Gibson tube-and-plate models, Epiphone (Recording A, Mayfair, etc), Leedy, Ludwig, Weymann, Gretsch, Slingerland, Maybelle, Rettberg & Lange, and about a zillion no-names, the list is endless.
http://www.ebay.com/itm/Vintage-Weym...0AAOSw241Ybav9
http://www.ebay.com/itm/VTG-1920S-VE...wAAOSwA3dYZDyQ
http://www.ebay.com/itm/Vintage-Leed...QAAOSwFqJWrRyz
http://www.ebay.com/itm/Vintage-1917...MAAOSw-0xYOMFr
http://www.ebay.com/itm/Estate-Banjo...YAAOSwPCVX4aRo
and so on......