I can guarantee you that a Vitamix is not a substitute for a juicer - particularly when you mention wheat grass. I owned a Vitamix for a few years and gave it away because it is nothing but an overpriced blender and there are blenders out there that are better and cheaper than Vitamix. I know, Vitamix pays some guy to visit my Costco every couple of weeks where he gives a carnival schpeel and tries to make believe that a Vitamix is a juicer - and it isn't.
When it comes to grass I used to have several racks of grass growing in trays by the window in my living room and juiced it with my Green Power juicer. You have to have a gear juicer for wheat grass to get anything out of it and even then you need a load of grass to get any juice and when you get it - it tastes horrible. It also never provided me with a single benefit and I still have Ann Wigmore's original book on her wheat grass juice discovery on my bookshelf. While I think she was sincere, I don't think that her story held much truth to it.
I have done several short term (10 day) juice fasts and also one of 21 days and you have to do them often for there to be any benefits or you will gain your weight right back. Again, I never found any real benefit from them and gave them up a long time ago.
The best kind of fasting that I've found for weight loss and health in general is the every other day fasting/dieting. Eat regularly one day and then no more than 500 calories the next. That also becomes difficult though because there are always family events that don't follow your schedule and it is difficult to stick with the program. Also in one of the books on the alternate day diet (either http://www.amazon.com/The-QOD-Diet-Eating-Every/dp/0977461408/ref=sr_1_1?ie=U...
it says not to do the diet if you are over 65. I'm in my 80's and never had a problem with it.
The Omega 8004 is a gear/masticating juicer though it is a single gear juicer. The Green Power (and others) are a twin gear juicer.
Regarding Omega 8004 and wheat grass - go to the top of this page to get a honest review on its ability to juice wheat grass.
I never had a problem with my Green Power for wheat grass as the gears were adjustable and if things didn't masticate properly you could loosen the gears.
I've had several juicers and there is no perfect juicer. You can spend a couple of thousand dollars and you will probably still have problems but because I didn't like wheat grass juice I use a centrifugal juicer - the Breville JE98XL if I remember right, and found it to be much better at extraction, easier to use, and easier to clean.
When you start juicing you open up a whole new world. Have fun!
If you own a Viatamix you know that in order to chop up veggies the instructions have you put ice and or water in the blender - because, it won't chop veggies without it! So, you can strain all the pulp out of a Vitamix chopped veggie that you wish, but you'll never separate the added water - that's where it falls flat on its butt. I know. I know the difference between Vitamix "juice" and real juicer juice - I've had both at the same time.
The bum review on amazon regarding the Omega filter problem was a recent review.
After the wheat grass juicing failures my main juice was carrot juice with a little celery juice thrown in. I could juice fast on that for several days.
While Vitamix is a good blender, it would never work with trying to extract juice from carrots for example. What I did find in the several juicers that I owned was that the Green Power - my first juicer, was slow when it came to carrots and would accept only 1 carrot at a time. It was difficult to clean - which is a major complaint about that machine but I learned to get it torn apart and cleaned in just a couple of minutes. (You have to clean your juicer immediately after juicing or you will have a major problem getting it clean. In other words, you can't juice and then let it sit for a few hours and juice again - I tried it.)
After giving away the Vitamix to a relative I bought an Oster blender for $60 - http://www.costco.com/Oster-Blender.product.11599298.html?catalogId=10701&...
and to tell you the truth it is just one small step below the Vitamix which Costco also sells - for $500. For me, the Oster does everything the Vitamix did.
When it came to my carrot juice there is no way you could beat my Breville - I had two of them and if I remember right the JE98XL was the second one owned and was an excellent carrot juicer. I could juice 4 and 5 carrots at a time - they ran right through and they have 2 speeds which is great for carrots. The pulp was actually drier than my Green Power, and so much quicker.
I made a major relocation a couple of years ago and I don't currently own a juicer but may get back at it.
I know that the Jack LaLanne juicers are cheap but have steered clear of them because of the mixed reviews. The review site at Costco is a LaLanne juicer that is a step above the original yet it too has very mixed reviews - 68 of them:
Some folks are really happy with them, others simply have had bad experiences. Breville (at amazon) also has juicers in that price range and I've had good luck with them.
When I'm buying products I will look at either the amazon site for reviews, or Costco if they carry it. There isn't a juicer out there that has "perfect" ratings and when it comes to carrots - which is what I juice, some juicers can become ugly - including my expensive twin gear Green Power which simply took its time with them, one carrot at a time.