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.

Well, you can always try Ebay, or Craigslist. I have a friend that got a barely used Green Star Juicer (a super expensive juicer) for about 1/3rd the cost of new. I just peeked on Ebay, and there are a lot of results, of varying quality/usefulness.

Jtc has an alternative with its omniblend blenders at a very attractive price. Speed is up to 38000 rpm with 3ph. you can even use the vitamix jar on it

Have you contemplated buying a cheaper, but Refurbished Vitamix?

But in the case of Vitamix blenders, the process of reconditioning machines is a serious, formalized 17-step process, and these certified-reconditioned blenders are what Holly Hacker, director of direct sales and customer experience at Vitamix, calls “truly good as new.” These refurbished blenders aren’t new, though. They’re all technically used and have been returned to the manufacturer, mostly by Costco customers.

I was researching this and there are a lot of Vitamix knockoffs now but they don't hold up(they literally look exactly like a Vitamix). It is hard to beat a Vitamix for horsepower intensive tasks(high friction) like making Nut butters or Milling flour especially with their generous warranty. I did learn about a couple options that work almost as well as a Vitamix for much less and would be fine for most users. The Oster Versa Pro and Cleanblend performed well in multiple independent tests that included high end blenders like Vitamix and Blendtec.

Food and drink places go bankrupt all the time. You could check asset liquidation web-sites to get your hands on a second hand one.