Millionaire singer Lady Gaga still shops for bargains in store sales and insists on using money-saving coupons.

The "Poker Face" hitmaker has netted a fortune since shooting to global fame in 2008, but she still watches the pennies and is adamant she is not ashamed of haggling with shop assistants to bag a bargain.

In a post on Twitter, she writes, "Why do people look at me like I'm crazy when I use coupons at grocery (stores) or try bargaining at retail, IM FROM NEW YORK WHERE IS THE SALE RACK."