The Music Score's Yamaha and Kawai Fun Facts
The truth about “Gray Market” pianos

The Webster New World Dictionary defines gray market as: "A place or system for selling scarce goods at above prevailing prices, a practice considered unethical although legal." Since these so-called "gray market" Japanese pianos are generally neither scarce, nor sold above prevailing prices, it is hard to see how the definition applies.

What, exactly, is a "gray-market" piano? Unfortunately, this term has been used by piano people in many different situations and circumstances, and the definition is not always clear-cut.  Other supposedly related names, such as "bootleg" and "trans-shipped" have been used by both dealers of new pianos and other interested parties to discredit pianos that, in many cases, may be perfectly valid and legal, but just not what they are selling. These epithets are most often used to refer to a brand-name piano that is being sold outside what are considered (by dealers of new pianos) the legitimate or accepted lines of manufacturer-dealer distribution for that brand.
Usually, to buy a new piano, you must purchase it from an "authorized" dealer, (i.e., one who is authorized by the manufacturer to sell their brand of piano in your area. Technically, only an authorized dealer can sell a "new" piano complete with warranty and factory support.) Being an "authorized" dealer is a big deal for the party who has earned that distinction, and you can bet your bottom dollar that they will do everything they can to try and make the most of the fact that they are authorized and no one else is (except for, of course, all the other "authorized" dealers in the state or country.)
Being so-called "gray-market" does not necessarily invalidate a piano as a useful or valuable instrument. But as they are frequently pianos from which the "authorized" dealers of new pianos do not make a commission or profit, you can be sure that "authorized" dealers will gladly point out any and all areas where the gray market piano may be suspect, or in which the gray market piano has, in their opinion, significant negative or compromising differences from what they are selling. Usually dealers of new pianos fault gray market pianos for not having any, or adequate, warranty coverage, or for being in some way incompatible, or inferior to the new pianos they sell, or on not having replacement parts availability; generally the same arguments they advance with same-brand used pianos being sold by competing dealers or by private parties. 
A gray market piano can be a new, "almost-new", or used, name-brand instrument that is being sold in an authorized dealer's area, but not by the authorized dealer, (or not by the dealer authorized to sell it in that area). It may be a piano that was not originally intended (for any number of reasons, marketing or otherwise) to be sold in your area, in your market, or even in your country.  Every piano, new or used should be properly adjusted (regulated), prepped, tuned and maintained by a professional piano technician. Give these pianos the same care and they will last as long as any other piano being sold with the same name. Why not? They’re made by the same company!

Now, there IS a difference in the quality of restoration of these pianos depending on which shop you buy it from. If the price is really low and the shop can't give you at least a 10 year warranty, avoid buying that piano! This basically tells you what they DIDN'T do to the piano and how they feel about the quality of the work they did do!