Quote: "it's like saying 'How can they charge £2500 for 3DS Max and only £45 for PaintShopPro?'."
Wouldn't Photoshop for $650 and PaintShop Pro for $35 be a better comparison?
However this said, they are in totally different leagues development wise..
It's always been the case that sound engineers pay through the nose for everything. I mean just look around at some of the products that do similar stuff from Yamaha and Roland, and this looks like a steal.
That said look on SourceForge and you get something which does the same just for free.
Personally I think the skin on it makes it look a little tacky, but guess that's just me. That's the same reason I didn't feel like splashing out on Fruity Loops, the product just feels tacky to use.