I just finished up a purchase yesterday. I bought a machine from a reputable Pinsider here local. I went over to look at the machine decided to buy (didn't even play it) I used Pay Pal with my Credit Card. I let him keep the machine til the money cleared his bank, then went over yesterday to pick up the game.
Smooth transaction all is good. You don't have to go cash on the glass, just go with a trusted buyer/seller. If anything had gone wrong I could have just filed fraud with my CC company no problem.