(donjuan: I don't get it... size for size, how can Petrofs be more expensive than Yamaha's C-series?)
For grand piano in the under $12k price range, not many good choices out there. See if you can find the discountinued Weber 5'7" (made by Samick), may be RX-1 or the G(something) series from Kawai. Not even sure if you an get a C1, may be Yamaha's G(something) series might work in that price range. But you should be able to get a pretty good used Japanese piano (10+ years old, perhaps 6 to 6-1/2 foot grand). Small (under 6-foot) Eastern European pianos like Petrofs are also possibilities.
donjuan wrote: "Petrofs can be much better than the C series. They are made in the Czech Republic, whereas Yamaha sends their pianos to many countries to be made for less labour costs."
donjuan wrote: "I played on Kawai RX Series, and I hated it!! The action was stiff and the keys were yellow to begin with- they use some new material that emulates ivory, butit feels like and looks like crap."
donjuan wrote: "I also Played on a 6' Yamaha G series and was dissatisfied with it. The G series is basically a cheaper brand f the C series, made with cheaper woods and less care. The one I played had a horrible buzzing soundboard, and a bent keybed that made it squeak like a mouse when certain keys are played."
donjuan wrote: "Personally, I think Samick makes too many pianos, and focusses on Quantity rather than Quality. If you do choose to go with it, spend a lot of time playing it and see if there are any little problems with it because if they bug you now, they will only get worse and lead to expensive repairs for a piano that is really not worth it."
donjuan, welcome back. You hate the Kawai RX series, I like them just fine. Our opinions differ, we have different likes and dislikes, and that's OK.