At a dollar a mile gross to the truck, 100 mile run, you would get $70 and your fuel would cost about $20 for a net to you of $50.
At 65% you would get $65, your fuel would cost $20, but if you got 10 cents per mile FSC, you would have $65 + $10 = $75 for a net to you of $55.
FSC is kinda like an adjustable mortgage. It will go up or down depending on the cost of diesel fuel. It also matters to which carrier your owner is leased. Some pay FSC on some deadhead miles, some don't. Bottom line, find out what the current FSC is and do your own math as above. Good luck with your choice.