Not sure I really understand the purpose of your question but on Envato's websites like Theme Forest and Code Canyon, you can see how many sales themes and plugins have made, and can obviously see the price as well.
And some themes have been purchased thousands of times.
For example, a theme that costs $60 and has been purchased 20,000 times gives a total of $1,200,000. I am not sure what the Envato commission or rates are these days.