Exactly in line with AWS S3, 10x cheaper over 10 years (actually it’s less than 10 years for google drive, but I think it’s ballpark close enough to keep the simple 10|10 relation, and yes other tiers / timelines vary a lot with the ratio, but I’m gonna cherrypick 
)
Extrapolating this we end up with permanent storage being 5x the current cost to store for 1 year (calcs here).