I bought when I first started collecting glass 5 years ago. You eventually refine your eye and your tastes (and usually the depth of your wallet/purse!).
:24: I used to collect the good stuff, these days if I am not collecting information it is the junkiest glass, in many eyes. These are the gems that no-one knows anything about. Chinese glass would certainly fall into such a category. Look at the junk produced in the 17th century and now lusted over

Mind you, I started off collecting what everyone consider junk 30 years ago and now it is prized and out of my pocket.