I have the following data:

Supplier, Brand, Retail Price, Volume

I would like to chart it as follows:

Suppliers across the bottom, with their respective brands above. The
position on the Y axis should be determined by the retail price.

Each brand would be a bubble. The size of the bubble should be
determined by the brand's volume.

I can not figure out how to get this chart done in Excel 2007. (I
have also tried powerpoint) Any help would be appreciated.

Regards

John