Muggle Money Exchange Rate?

[Chys Sage Lattes]

No: HPFGUIDX 126600


Ok, so what is it, does anyone have any past discussion references
they could send me to tell me exactly what the exchange rate is
between Muggle and Wizarding money? Or do we know the knut to dollar
rate?

I think JKR said there isn't one, but that's bull, even if that's 
what she intended. There has to be one since people can exchange 
muggle money for Wizarding money - Hermione's parents did this 
themselves. Otherwise you'd change a one dollar bill or a $10 for 
50 galleons, and that ain't right if the goblins don't know the 
difference.

Hagrid payed an owl 5 knuts in book 1, Hermione paid an owl a couple 
knuts sometime later, a wand was something like 7 galleons right? How much is a broom?


So what is it?

*very curious*

Chys