I think the use crumpled envelopes because they are supposed to be carried around, have money stuffed in them, and passed from guy to guy. If Chris is running his bookmaking operation, he probably has a number of different guys doing the collecting, and maybe the envelope has passed through three or four guys before he gets it. And it's not like they're handing gift certificates to Tony, they're handing him cash collected from degenerate gamblers. The crumpled envelopes make more sense.