love the old radios

i love old radios and have collected a few... nothing special 10 dollar philcos. i'm into antiques and frequently see them in antique malls etc, but never know if prices are worth it. is there a good source for determining value and whats a good buy? i want to take a few shelves of my listening room and dedicate to old radios, more a display rather than for listening, any suggestions on models or sources (ebay of course)... thanks ahead for any input
tyler