I've determined it's basically impossible to do that if you don't own a dedicated high-bandwidth seedbox. That costs a bunch of money
I pay $6 or $7/mo for Ultra.CC and it's 1TB storage with 4TB monthly bandwidth. I never exceed the bandwidth, but the 1TB allows you to seed for quite some time. I set rules to keep stuff until a minimum 10:1 seed ratio, and some rare stuff for 50:1. Some stuff is so minimal/small, it's there indefinitely.