Good (cheaper) alternative to Vitamix Blender
I don't think it's possible. You are talking about restaurant / bar quality blender (like Vitamix, Waring, or Blend-tec). Cheaper units will not have the horsepower or quality of construction to do things like smooth blends of ice in a drink, generate enough friction to heat a soup from scratch, or grind flour from nuts and grains. 

Even if your blender will handle some of these things initially (like blend ice, I'm skeptical any cheap mixer will provide enough heat for a soup), I think your blade / motor will quickly take enough abuse that it won't be able to continue to perform. 

Update: Since initially posting this answer, I've actually bought a Vita-Mix (I'd been lusting for quite some time). I now feel more strongly that my answer is right. I've used it three times in the first 12 hours of ownership: 


Nut Butter - I made a pistachio nut butter that required nothing more than 2 cups of pistachios and a tablespoon of oil. It came together really quickly and has a lovely velvety texture. 
Pureed halved peaches - these ended up complete liquid with no texture / fiber left from the fruit. Exactly like Looza Nectar, but fresh. 
A smoothie. The smoothie had zero ice chunks in it and was professional quality. 


I have never seen a cheaper blender capable of the quality of any of the first three things I've tried. I'm afraid you're out of luck.