My grandma has an older TV that does not have built-in support for Closed Captions, so I would like to get a Closed-Caption Decoder. What kinds of features should I look for, or what brands/models do you recommend. When I searched online, all the decoders I found were over $100. The used ones on e-bay seem to be going for about $10~$30. Are the ones on E-bay any good?