A while back I called in at a local op shop looking for a picture frame of a certain size.

I'd been given a large piece of artwork for Christmas and didn't fancy spending more than $100 at a framing shop.

The op shop didn't have anything suitable in stock, but a fellow customer piped up that she had one at home she didn't need.

I duly popped into the address and discovered that "home" for the op shopper - who was on first-name terms with the staff - was the Milford beachfront.

My money-saving radar went up. This owner of a $3 million property was op shopping even though she could almost certainly afford to buy new. Good on her. She reminded me of former MP Muriel Newman who wrote a book on penny pinching the old-fashioned way.

Even better, Ingvar Kamprad, founder of the mega-successful Ikea chain of home stores, is also one of the world's best-known frugal billionaires. Kamprad is a man after my own heart. According to his Wikipedia entry he:

* Drives a 15-year-old Volvo.

* Flies only economy class.

* Often visits his own stores for a "cheap meal" in the cafeteria.

* Buys Christmas paper and presents in post-Christmas sales.

* Gets employees to always write on both sides of a piece of paper.

The oft-quoted investor Warren Buffett, number three on Forbes' list of the world's wealthiest people, is likely to agree with the Swede.

"Whether we're talking about socks or stocks, I like buying quality merchandise when it is marked down," he told Berkshire Hathaway shareholders in his 2008 chairman's letter.

The self-made wealthy don't get rich by living in hock to pretend to the neighbours they are successful enough to drive a late-model Mercedes.

What people like Kamprad do is avoid spending creep every time their income goes up.

Or at least they keep their needs in perspective.

I run into my friend, the North Shore op shopper, from time to time and she's always immaculately presented. She's married to a well-known local businessman and I bet her neighbours on Millionaire Row don't realise that some of those designer outfits are new only to her.

Like Kamprad, however, she has built their wealth and retained it by being sensible rather than letting status go to her head.

That's not to say you need to be in business to retire wealthy. Ordinary people in ordinary jobs take the same approach to spending as these folk and build up sizeable retirement portfolios.