Try searching around, this topic has been covered many times.
Anyways to answer ur questions, theyre about $200 each. Theyre well designed. I still like the 19 design over Yamato's 19. As for the 21, you can see from Graham's Yamato 21 review that it doesnt stand up well at all in gerwalk mode and theres plenty of flaws here and there too. One correction tho, theyre a bit bigger than 1/100 scale. Even tho it says 1/100 on the box, the actually scale is closer to 1/72. Its more or less non-scale. None of us really know what scale they really are...