Others here have addressed the fact that they are imported for around $5 each. Then often sold for nearly that. This is the main problem.
Savs, are a mid sized monitor, to successfully keep them, you will have to spend up to 20 dollars a week or food and electricity. Of course, there are ways to lower that, but most buyers are impluse buyers lured in by the low prices and are not able or aware of how to do that.
Second, a midsized monitor REQUIRES a large cage. That means, ten feet long is about minimum. Of course, you could use a smaller cage, but then, you have to KNOW what your doing. The problem here is, 99.999% of Sav owners are newbies and do not know what there doing.
Third, Savs are a "lost leader" in the petshop industry. Pet shops do not make money on them. They make there money on the products they sell with them, including the food they consume. The problem here is, those products are NOT good for the monitor. And soon that monitor dies and is replaced over and over.
While it was mentioned they are imported by the thousands, its closer to several hundred thousand a year. Of which 99% die within a few months.
Just for fun, take the average lifespan of a midsized monitor, say 12 years. Over the average lifespan of a Sav, 2.5 million have been imported. This is sad, As I guess its a good thing they die, or our country would be covered in them. If they were actually bred in captivity, there would be tens of millions, hmmmmmmmm again good thing that does not occur.
Next, its respect, a CHEAP price, does not instill respect for the animal. If the monitor would actually cost more, like a few hundred bucks, then more folks would respect them enough to actually invest some time and money to keep them.
Lastly, A good beginer monitor SHOULD BE SMALL, that way, folks could actually keep them in a cage thats appropriate to their size. And feed them appropriate to their size. An example is, an ackie eating a large cricket is comparable to a Sav eating an adult mouse. At a petshop a cricket is a few cents, and a mouse is a buck and a half(both aprox) Which one is going to be fed properly by newbies???? Again, no cheers here