TVs made after 1993 with screens 13" or larger MUST have closed-captioning capabilities built in. If you have an older television, you may be able to find old decoder boxes on eBay or a similar resource for $10-$20 not including shipping.
Alternatively, you may want to look in TV repair shops for repaired televisions at low cost. Just make sure the date on the back is 1994 or newer and test the caption display before you buy.