Yes it would work and it is expensive! - Yes it would work, but for the nutritional value.. it is very expensive (holding one in my hand right now..)
It also depends on each individual as to what you want to achieve. If it is high antioxidant then yes Acai is good however it pays to check your products as Acai is super potent in pure acai form - freeze dried and from reliable sources plus independently tested to ensure integrity after manufacture/packaging. In fact for less price I have come across one which is ten times more effective.
I would use the MonaVie for taste alone.. there is one downside, for me, and that is that it contains sodium benzoate which does have some controversy (when it interacts with certain artificial colours it has been shown to contribute to hyperactivity, and a different aspect is shown here http://www.ncbi.nlm.nih.gov/pubmed/19294673?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum