From a recent visit to the National Air and Space Museum:
Behind and above, a Piper Cub (derivative of the Taylor Cub being advertised).
Adjusted for inflation, if we assume that the advertisement was from 1931 (first year of production), the “costs no more than a medium priced car” price of $1,270 is around $21,000 in 2019 mini-dollars.
[Note that the manufacturer apparently did not expect readers of the ad to be surprised that a person identifying as a woman (based on clothing) would be the owner-pilot. This was before Americans agreed that women are the new children (quoting a Facebook post in which a woman who earned a Private certificate in 1970 was “an original feminine trailblazer”, fully 60 years after the first woman earned a certificate).]