I've been using AWS S3 for many years and am no stranger to some pretty jaw dropping S3 bills. I recently learned about S3 Lifecycle Rules and was excited to learn I can greatly reduce my costs by migrating files to certain 'Tiers' (Standard, Intelligent, Glacier to name a few).
Using this approach, I've managed to cut a $6,000 / month bill to just under $2250.
Theres a bit of a learning curve regarding how Lifecycle Rules work and how to set them up. I've created a video summarizing how it works (with a step by step tutorial coming soon).
Video is available here: https://youtu.be/iDYWAasynzQ Hope this helps and I'm happy to field any questions.