"Lloyd E. Sponenburgh" lloydspinsidemindspring.com fired this volley in
. 3.70:

They're also for engines that are made in the tens of millions per year
to be 'throwaway' devices, and for which they need to supply parts to
make their market buy the engines.

You also might compare the prices.

I can buy a name-brand 5HP engine all-up for $150 bucks on sale. Good
quality industrial quality air pumps sell for eight times that; usually no
sales.

Lloyd