"Test Driving" a stone

Labhraín

Ok, I got some really good feedback on my post yesterday about Black Tourmaline and as I browse through jewelry pieces, it got me thinking:
before buying a piece of jewelry or a sphere or wand or whatever, do you "test drive" the stone first? In other words, would it be more prudent to buy a tumbled stone first to see how you get along with the stone, rather than go out and buy, say, a $40.00 bracelet or chunk of crystal for a bookshelf or something like that? How does everyone else test a stone before they decide that's the right stone for whatever piece they are looking at? What are your "qualification methods?"
 

Milfoil

Usually it's how it feels, even online you can get a feeling for a particular piece when you spend a little time looking at it.