Mesh
Silicon Audio
Let me explain:
Before X3, I never owned Melodyne. I got the X3 upgrade for $149. From that, I got an offer from Melodyne to get Editor for $149. That's a total of $298.
Before I upgraded to X3, buying Melodyne Editor direct from Melodyne would have cost me $399 - That means that I got Melodyne Editor for $100 less than retail and X3 was effectively free!
Thanks Cakewalk and Melodyne!
That might work well if your primary goal was to get Melodyne. 
Well, no, actually my primary goal was to get X3. But... I have always been interested in Melodyne - it just never came along at the right price. So I jumped at it when the upgrade was offered. I then examined just what I had got for my money and was pleasantly surprised at what a great deal this all was for someone like me who never owned Melodyne.
I vary rarely have much money to spend on things like this. So even though $298 is actually a lot of money for me, I feel I got incredible value.