Your Grandma's rocker is better looking than a lot of sewing rockers out there, but the fact remains that it is just a nice rocker...with 9 spindles. In today's depressed market, it would stand out from the rest, but would probably still struggle to bring $100. Years ago, there would have been more appreciation for it, when some buyers sought out unusual designs or spindle count.
(As I'm sitting here, I'm looking at a beautiful triple press back rocker with curved arms and 9 turned spindles. Years ago, I think I paid $250 for it, and thought it was a bargain. Today, if it was offered for sale, it might bring half of that.)