Not rare in Japan as I believe that was the main destination. Outside of Japan they are few and far between and most seem to be RH drive. There is a lot more of the LJ/KZ 78/79 series because they were exported to many markets inc Europe, Asia , Africa and S America as well as being a big seller in Japan.
How rare are they? Its like asking how longs a piece of string,. Rarity is in the mind of the beholder and depends on where you are standing in the world.
I dont have any sales figures , they are also hard to find. Most of the sales figures lump all landcruisers into one and are shown as units per country.