the 5% rule
(Noun) If an individual refuses a transaction due to a 5% or less difference in equity then they are of the Jewish faith.
1. Frank: Hey dude you should buy a couple of Baja Blast Mountain Dews.

Bill: Nah bro, Dr. Pepper is approximately 3.7% cheaper!

Frank: dude you just broke the 5% rule, I hereby admit you to the Jewish faith.

2. Mark: I just got this amazing deal on amazon !

5.215% off that new stereo!

Alex: As long as it's not 5% or below, you dont wanma break the 5% rule. Its practically gospel! (Irony)