I've not done any busking in years but the one thing I was told over and over again back in the day, is that you close with the money maker. . . the routine that is going to get the wallets to magically open and drop dollar bills into your hat.
It really doesn't matter what the trick is, as long as you can play it up and generate interest enough to get the money. . . the routine MUST be part of your pitch. This is why many buskers close with a routine involving cash (any number of monte effect, sidewalk shuffle type routines, etc.) I found myself doing the old Svengali pitch as my closer. . . not only did I sell some cards, I got the tips as well.
DON'T FOCUS ON THE TRICK, LEARN TO GIVE A SOLID SPIEL!