In fact, a vacuum level is very logarithmic.. So a 20 buck pump will give you about nothing.. same a using an air compressor..
A full high level 2 stage will bring you at -29.7inHg. with a small 1hp Gast, you will get about -27. and a 1/3 .. 1/4 it will be at -21 around.
You will still be resin rich. Still better than a wet layup, but not the best. Over cnc , for cutting, you will got the same result,.