A "Bob" refers to the British nickname for a 1 shilling (5 pence) coin; thereby "Ten Bob" is a 50 pence coin. (Archaic: there was previously a Ten Bob Note)

Mostly used in South Yorkshire, England, a "Ten Bob Millionaire" is a derogatory term someone who dresses and acts like they have a lot of money and status when in fact they have very little (i.e. Ten Bob)

They buy things to make themselves look more important than they actually are. They act like they are important and have a very high opinion of themselves, while deeming other to be below them and beneath contempt.

the thing that you don’t have when you’re phones percentage is over 20

Someone who drives a Caddy, but cannot make the payments. Someone who has a new Lexus but lives in a trailor park. Someone who wears fashionable labels, but cannot afford lunch. Someone who just got their paycheck and is spending it to impress rather than paying their bills.