You invest your time at work to recieve money, so as the cliche goes "Time is money". This is how I have always viewed purchasing goods, such as realzing that spending $20 on a 2 hour IMAX movie would cost me the same amount of time at my retail job.
This app allows you to enter your hourly wage or yearly salary. Sales and Federal Income Taxes are automatically calculated. A helpful visual is also provided to better understand how long you would need to work.
Calculations for average state and local sales tax can be seen here.
Calculations for Federal Income Tax provided by this NPM Package.