Yup! I believe they went right up to 29", but I suspect they're quite rare. 20" is better to come by, but I think unless you're lucky, will still go for several hundred dollary-doos.
There was one on Gumtree the other week that went for $200, bummed I couldn't get it because it would've been perfect. I think the time is perfect right now to get one because I reckon they'll go the way of other retro gaming devices and skyrocket, but that's only happening in a few places and only to desperate people.
I just got lucky with mine, $80 for two 14" on eBay and $50 delivery from NSW to Vic