If you put the data on Storj DCS, it would run about $40k/month for list pricing with global availability and encryption. I'm sure you could get a deal if you asked though. It has S3 compatibility, so would be plug and play with whatever you have now. Egress out of AWS would be free.
Way cheaper than AWS, and a lot less headache than trying to run it all yourself.
There is discount pricing over 100 TB. Its a tech demo so Tadigrade.io sponsors it. Pretty powerful demo on easily storing large amounts of data especially when Github goes down.
It is a tech demo of https://tardigrade.io, because easily storing all of Github certainly gets peoples attention.
Its only expensive because cloud providers overcharge. The listed prices on Tardigrade start at half of Amazon S3, and there are significant discounts if you are storing more than 100 TB.
Way cheaper than AWS, and a lot less headache than trying to run it all yourself.