Erm 35,786 km is geostationary orbit, perhaps we have a different understanding of Newtonian celestial mechanics, your statement to wit -

" Well, mass cancelled out in the equations. So the mass of the vehicle doesn't matter. However much energy it takes to get to orbit, it will take 90% of that energy to slow back down."

Your understanding of mass seems to differ from mine, in terms of the economics of the equation.

To my limited understanding, the more mass you have, the greater the cost to get it to orbit, sort of dollar * Kg, if part of the mass exists up there already, you need less fuel, to get less fuel up there already.

To understand recursion, first you must understand recursion, lol.