Ok, so along with cutting costs, the standard box with model pictures also give SST products a homogenous look.
Also, I feel that several of the box art pieces detract from the product, by wither being too muddy or inaccurately portraying the model. For example, the basic plastic MI box, and the warrior bug box don't exactly showcase the product as you will be receiving it, and ascetically the covers don’t appeal much to me personally. The same goes for the hopper box, and while the tanker art is a lovely piece, it really isn’t the tanker that you’re getting in the box.
And I really can't say that the Reliant art, or the WASP art is an enticement to buy.
Oh, and can you imagine the buyer’s remorse if someone bought Stalwart Field Generators on the basis of cool box art?
I think painted pictures are an honest and good choice.