I tried this challenge a few years ago. It starts good but it gets hard to have the cash available to put into a jar every week. It's not that you don't have the money, it's that you don't have the physical cash to put in the jar and if you miss one week, it gets put off until the next and it gets harder to catch up.
What works for me is to put the same amount into a savings account before I pay any other bills. For me, it's 10% every two weeks. That isn't really that much money once you get used to paying it and chances are it will be more than $1500 by years end unless you are putting less than $25 a week. It used to go into a savings account but now I put it into cryptocurrency which gives me more profits on the gains instead of losing money on inflation when it's sitting in the bank.
RE: Shocking News: Americans and money