I'll go a bit further on the gray markets.
Most brands, such as Kubota, do not allow their parts departments to provide parts for these tractors if imported to the US from another country.
Kubota has gone to great lengths to keep their grays out of the US market, including suing US distributors and others, and making sure that customs officials are aware that these tractors should not be imported.
I understand that Yanmar may also be going so far, but I'm not sure of that one.
Sometimes the tractors get relabled as Zin Noh (sp) tractors, but are either Yanmars or most often Kubotas.
Kubota has a list of gray market tractors on their website, so one can check the numbers before buying. Often, there is a US equivalent tractor model so many people just use that number to get parts, but it is not infallible, as sometimes, different parts were used on the grays than the US models.
A good deal can sometimes be had by buying a gray market tractor, but as often as not, it may cost a lot more in the long run as parts may be difficult or impossible to obtain, particularly on the Kubotas.
Another problem is the sale of so-called rebuilt grays where they are taken to Vietnam or other southeast asian country to be rebuilt. Often they do nothing more than piece together a tractor from other carcasses and repaint them. There have been many reports of them being CRAP.
Unless one is really good with the mechanics, it's probably best to avoid gray market tractors. Personally, the most problems I've seen with grays is bad radiators as the #1 problem. There are others.
Many Yanmars were sold as US models, one can ferret them out, but many more are brought here from Japan and those other countries.
John