It was in the 1950’s ...According to old advertisements by Hoover and other vacuum cleaner manufacturing companies, vacuum cleaners ranged from $35 to $65 in price depending on the model.
http://www.geyservac.com/information/vacuum-cleaners-1950.html
A vacuum costing $35 to $65 in 1952 would cost $262 to $487 today.
One reason quality has gone down is that for many types of products people aren’t willing to pay more for the quality. Low quality drives out high quality unless people are willing to pay a premium for the quality product.