I'm sure if you post up what type of Landcruiser your looking at buying, check it previous MOT history online to see how much work its had / advisories and check the vehicle over you can use the short MOT as a tool to get a better deal, It will automatically have another 6 months added to the validity, but still need to be roadworthy, up to you I guess to define roadworthy, the lads on here will no doubt give you some more advice