As Mulder said, it takes a lot of energy to dig up the shale, crush it, heat it and get the oil out. When you hear estimates like "$80 / barrel" for shale oil, keep in mind those are usually calculated using $40 / barrel mideast oil to build and fuel equipment and extract the shale oil. If mideast oil is $262, shale oil could cost $200 / barrel or $400 / barrel, or maybe only $100 / barrel.
Nuclear reactor heat, which is usually wasted in condensors could be used to heat the shale. Or a dedicated heat exchanger just for shale oil extraction. Of course it would require a nuclear reactor but it would be much "cheaper" in terms of energy to get the oil from the shale.
"As Mulder said, it takes a lot of energy to dig up the shale, crush it, heat it and get the oil out."
Er, that is why in-situ methods will be used when shale oil is finally commercialized. Digging it up and processing it that way is too inefficient, but in-situ is more efficient.
No, that is not how it works. Facilities do not typically buy fuel from somewhere else unless they are in the middle of an industrial area. On the Alaskan North Slope, at the Alberta Tar Sands, on platforms in the Gulf of Mexico and oil fields in the Middle East, natural gas and diesel from small topping plants are used to provide heat and run generators.