OK, so the fairest, most accurate way I see of doing this is this:

Same TYPE of vehicle (SUV, hatchback, sealed trunk, etc.)
Sealed box (least amount of variables)
Amp of your choice (obviously different subs require different amounts of power)
Wiring of your choice (again, different amps and subs require different wiring)
No sound dampening
Your 10" sub cannot exceed $350 new


This would somewhat even the playing field and put to test the argument of sub vs. sub without taking into account how built other aspects are (which would be theoretically limitless). $1000 cash, and whatever anyone else wants to bet. Toby can hold all money, I trust him.