If you already have a technician competent in voicing/regulating pianos, then pick any NEW C3/RX-3. Otherwise, go pick the one that's been prepared better (or closer to your ideal anyway). While the underlying build quality may be the same, the preparations the dealer do will make a difference. Even if you have your own tech, a better prepared piano of the same price will leave less work for your tech to do, take fewer of your tech's hours, and still save you some money that way.
USED pianos -- I'd say go pick one yourself, since the conditions of the pianos (nature and amount prior abuses) will vary.
("Handmade" has got nothing to do with this... "handmade" or not, some makes are simply "more consistent" and some makes have more varied "individual characters" among their pianos.

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