Russian Roulette with Jigsaw Puzzles

This is my third jigsaw puzzle purchased from a thrift store, and it was complete, no pieces missing.  Keep in mind that when a puzzle is donated, there's no guarantee that it is complete, or that it didn't lose any pieces while sitting in the toy section in the store, where things get a little wild with youngsters sometimes.  I always tell myself,  ah well, even if there's a piece or two missing, I still  had fun working that puzzle!  But when this one came close to the end and I looked at the quantity of pieces in the box and what was left to finish, it didn't seem enough, and already I was beginning to feel some major disappointment.  It made me decide to stop my 'Russian Roulette' with used puzzles; after three lucky, completed puzzles, it's going to be new ones only from now on!