not sure if the price difference from stock to a $8500 diesel would be worth it as far as gas savings. curious.
I had a diesel conversion done on a 3rd Gen, and can tell you unequivocally that the gas savings will not pay for the conversion. The costs of a host vehicle (find one with a blown engine and good frame and interior and you can go really cheap), 1/2 cut from Japan (mine had about 30K miles on the engine), and the labor to do the conversion (unless you have the time, space, and skillz to do it yourself. I do not.), add up quickly.
However, I have absolutely no regrets! I generally run B100 when available, and love the sound, smell, rumble, and torque I get from it. I think that I had this conversion done more out of protest that we Americans don't get access to any of the wonderful mid-sized and small trucks with good diesel engines in them. And I hate reading all of the articles with car executives stating that Americans don't like or accept diesels.
I get stopped at lights, gas stations, parking lots, and everywhere else asking me where I found a diesel Runner. I love my "Beast".