The Corrimal couple are regular Mercury readers and had been collecting entry coupons to the lucky door prize during the past week.

But they never imagined they would actually win.

"It is excellent, though very unexpected," Mr Tobin, 46, said.

The couple are both a few years away from retirement but attended the expo to gain a head start on their options.

"We went out to the expo to get a good start in things like financial planning and to get our wills set up," Mrs Tobin, 45, said.

"We spent a couple of hours out there and it was really helpful."

The $5000 lucky door cash prize has come as a welcome relief for the couple, who have four daughters aged 15 to 25.

They are both off work at the moment because of health problems and are soon to become grandparents for the first time.

"The girls were really excited when we told them, it has just been so unexpected," Mrs Tobin said.

Many members of the community attended the expo, held at Kembla Grange, looking for retirement-specific information on everything from investing and finding a retirement village to health and travel clubs.

Mercury promotions manager Maria Thomson said the event, hailed a success by organisers, stallholders and visitors alike, continued to be well-received.

"The expo attracted a lot of interest again this year, particularly the seminars, which were very well attended," she said.