Math People: Need an Equation, Please

When I sell items in the Auction House on World of Warcraft, the game takes a 2.5% cut. So ferinstance, if I sell an item for 1 gold, I get back 97 silver 50 copper. To think of it another way (for those who don’t play World of Warcraft); if I sold an item for $100, I’d get back $97.50.

I need an equation to use so that when I sell an item at Buyout (the WoW equivalent of eBay’s But It Now), I get an even amount of gold back. So ferinstance, I want to sell an item for exactly 1 gold, I would set the Buyout price at [insert your fancy equation to determine price here].

TIA

For a simple equation, I think dividing what you want to get by 0.975 would yield the right price to set. Example: I want to get 100. I should set the price at 100/0.975, which is equal to 102.564 to get 100 back, or at least roughly 100 back.

X gold net = Buyout Price of X gold, 2X silver, and 50X copper.

Normalize by removing the Y-hundreds of copper and increasing the silver by Y. Then remove the Z-hundreds of silver and increasing the gold by Z.

Is this what you’re looking for?

Thank you, randomface, that was exactly what I’m looking for.

Do this.

Since you specifically asked for an equation, here it is:

SELLING PRICE - 0.025*SELLING PRICE = GOLD BACK

(1 - 0.025)*SELLING PRICE = GOLD BACK

0.975*SELLING PRICE = GOLD BACK

SELLING PRICE = GOLD BACK / 0.975

Well, that’s better than the answer I was going to give. Multiply by the reciprocal: 1.02564 102564 102564 102564…

For small percentages, simply adding the percentage that is about to be subtracted is good enough. Sell the item for $102.50 and you will receive $99.9375. This approach gets worse as the percentage increases, but it’s still only 1% out at 10% (90% of 110% = 99%).