James and Glenda Butler, of Dunedin, decided to sell the Mailer St cafe after Mrs Butler had a ''bowel cancer scare'' and has been recovering from surgery.
Mr Butler said as the illness came on quickly, they missed the opportunity to tell their loyal customers the cafe was being sold.
Since word of the sale spread, the support had been ''phenomenal'', Mr Butler said.
However, some wellwishers had also asked for recipes, Mr Butler said, laughing.
The shop had been a cafe for more than 40 years and since they bought it as a going concern in 1986, the furnishings had remained unchanged.
A phone number on the menu board has five digits.
Many of the customers were the same, too.
''We didn't change anything, because the people that came here, that's what they wanted.''
The first customer they served came to the shop every day it was open and bought two cakes and two sandwiches.
The cafe was open five days a week and the food - including cheese rolls, macaroni cheese and scones - was made on site.
Mrs Butler said a woman held an afternoon tea in the shop to celebrate her 100th birthday and another woman bought lunch for nearly 20 friends after winning $1 million in a Bonus Bonds draw.
The woman had repeated the gesture every year for the past six years and allowed her friends to select whatever they wanted from the menu or cabinet, she said.
Mr Butler said another regular customer often played his recorder in the corner but the musical instrument was not enjoyed by everyone.
A customer at the cash register told Mr Butler: ''If you think I'm paying entertainment money for that, you can forget about it.''
The customers made the work enjoyable, Mr Butler said.
''It's been a way of life and I'm going to struggle to get into another way of life,'' he said.
Mrs Butler agreed.
''It's been quite an amazing lifestyle.''
Mr Butler said the shop did not have eftpos and if customers had no cash they were told they could pay next time they visited.
''And people never let us down; they all came back.''
Harcourts business brokers Karen Thomson said several people showed interest in buying the cafe and a young Dunedin woman would take possession of the business tomorrow.
The woman planned to remodel the interior of the cafe before it reopened but had not indicated whether she would change the menu, she said.
