There is no reason why you shouldn't consider buying this tractor. Although it was made for the Japanese market the biggest difference between it and the european models is the colour of the paintwork.
Spares are available from places like Tracpartz (
www.tracpartz.com) and some information on it can be found here:
www.tractordata.com ***8250; Tractors ***8250; Kubota
Manuals for grey market tractors can be hard to come by but if you find the european equivilant with the same size engine such as the B7200 you can get a lot of information that way.
All I would say is approach it as you would buying any vehicle, ie; judge it on its condition. If the engine runs smoothly without smoking, there are no suspicious noises from the transmission or signs of oil leaks etc then there is a good chance that it will serve you well.
One thing I would check with any kubota no matter what its origin is the oil in the front axle (on 4wd models).
I found that the dealer I bought mine from had pumped grease in rather than oil. My tractor is under warranty and I suspect that to avoid the possibility of having to replace the axle oil seals if they leaked in the warranty period the dealer reasoned it would be less likely to show if he put grease in.
I have cleared out the grease and filled the axle with the correct oil. Luckily for the dealer there are no oil leaks as a result!