Language changes and evolves according to the trends and fashions of life. I imagine that the expression to buy something “on the never never” has probably reached the end of its useful life.
It means to buy something in small instalments. Before credit cards came along and the banks decided there was money to make from that business, it was customary, particularly in the first half of the 20th century for people to finance large purchases by using payment plans that stores, farmer’s societies and other cooperatives offered. Sometimes this was called hire purchase, meaning the buyer “rented” the product for use until they had paid all the instalments whereupon they became the owner. Other arrangements involved paying sums on a weekly basis until all or most of the product had been paid for and it was delivered to you.
We bought the fridge on the never never and won’t finish paying it off until next year.
In the past, people often had to wait to acquire something new and household management involved setting small sums aside each week for the different future purchases they were working towards.
Once credit cards became popular, the idea of laboriously saving up for appliances etc. became old fashioned and people like my parents’ generation who were brought up in the depression and would comment on the younger generation getting everything so fast seemed out of touch.
Not even thirty and they have a two story house, two cars, a timeshare and a huge wardrobe! Talk about having it all!