you can do a revs check.. and in qld (not sure what other states do) you can do a vcheck..
you just need to check that the VIN & engine number match.. also can post the VIN in the "VINs you want fasted" thread and someone will let you know all the details on the car (colour, make, engine no) and you can check to ensure the car is all to spec.. this ensures the engine hasnt been replaced.. that it is the car that they say it is, etc..
now in terms of the k's.. done worry about them.. they are most likely changed.. mines on 57,000 lol
the guy is an importer.. seems a little cheap for the exchange atm.. just dont go for the cheapies if you got the money.. cause there's always a reason they are cheap