First what I had to do was figure out what the conversion rate of Galleons to Pounds were, and then convert the Pounds to USDollars. I'm going by the old standby of 5 Pounds to a Galleon for conversion purposes.

$6.45 for 1 Galleon

$0.38 for 1 Sickle

$0.013 for 1 Knut

Now please note that these rates are rounded up/down and thus are not perfect, but will suit my purposes. While there are 27 Knuts to a Sickle, I'm sticking with these rates for simplistic reasons.

I'm going to stick with a car(C) for right now and it'll be priced at $15,999.99 which is decent, but not (relatively) expensive. I started by dividing C by Galleon(G) and was presented with 2480.618404651163. With 2480 being the number of Galleons, all I have to figure out now is how much is left over for the Sickles.

From there I took (G) and multiplied it by .618404651163(T) to get our remainder in USD. This came out to $3.98871 which I rounded up to be $3.99(R). After dividing R with Sickle(S) the result was 10.5 Sickles.

A similar process lead me to there being 14.615 Knuts. Naturally I rounded the number up and here is how much that car would end up costing Harry.

2480 Galleons, 10 Sickles, 15 Knuts

Thank you for your time reading this.

This process can be used for any item you want to have your favorite wizard or witch buy...yes, I am that bored.