Amazon offers Amazon Prime members the Oster Stainless Steel 4-Quart Pressure Cooker
with free shipping
. (Non-members can get free shipping with orders of $25 or more; otherwise, shipping adds $9.71.) That's the lowest total price we could find by $29. This 16.7" x 10.8" x 8.2" pressure cooker features an aluminum base, Bakelite handles and knobs, stainless steel lid with auto lock, and mirror-polished exterior.
Amazon Prime membership is $79 per year; however, Prime is free for college students for six months, and free for parents and caregivers for three months. (Note that currently there's a waitlist for Amazon Mom.)