lol I like where you're going with it.  I have another similar idea.  Make a calculator where the answer is always "10% above profitable break even point of the most efficient cards, ignoring the initial cost of the hardware, but counting only the median price of electricity" because that's where it will be in a few months.  That's because new miners will keep starting mining with no stopping them until it's no longer profitable.  Then most new, some longtime, and other random miners will stop mining.  People have absolutely no reason to mine if they're actually losing money on it due to the sheer volume of other GPUs working on it.

Transaction commissions are not going to be a factor until after the 2012 split and after there's 100x more volume at the absolute earliest.

That's why I'm reconsidering purchasing further hardware to go above a single 5830 rig.  The thing is, a triple card rig will pay for itself about 25% faster so I dunno.  There are 0 for sale on planet earth anyway lol.