Discount on order total

[MickeyBlueEyes]

Hi, I'm trying to put a wholesale site together. I'm using joomla 2.5.6 and VM 2.0.8e
What i need is a Discount on order total, for example if you buy from:
1-499$ no discount
500-1999$ 40 % discount
2000-4999 $ 50 % discount , and so on.
Haven't found any workable solution.
Any Ideas?