In regards to the 1920's, which I assume is the period youre asking about, the prosperity of the 1920s led to new patterns of consumption, or purchasing consumer goods like radios, cars, vacuums, beauty products or clothing.
Technological innovation influenced more than just transportation. As access to electricity became more common and the electric motor was made more efficient, inventors began to churn out new and more complex household appliances. Newly developed innovations like radios, phonographs, vacuum cleaners, washing machines, and refrigerators emerged on the market during this period. These new items were expensive, but consumer-purchasing innovations like store credit and installment plans made them available to a larger segment of the population.
Despite the fact that the promise of more leisure time went largely unfulfilled, the lure of technology as the gateway to a more relaxed lifestyle endured. This enduring dream was a testament to the influence of another growing industry: advertising.
The mass consumption of cars, household appliances, ready-to-wear clothing, and processed foods depended heavily on the work of advertisers.
In terms of buying it all at once, before the advent of mass production, goods were usually manufactured on a made-to-order basis. Once mass production was developed and perfected, consumer goods could be made for the broadest possible market. Anything consumers needed or desired could be made in larger quantities. Mass production resulted in lower prices of consumer goods. Eventually, economies of scale resulted in the most affordable price of any product for the consumer without the manufacturer having to sacrifice profits.