Me personally? We back up dozens of TBs. So for me...yes. Would other people use the entire 500GB of space? Who knows. Most places have cheaper, lower disk space options.
Glacier is extremely expensive (and slow...it takes up to several hours to get your data back). It's all on tape backup drives. Not at all suitable for backups in a production environment. Who can wait hours to get to their backup data?
And why the hell would you ever want a "reduced redundancy" backup? ROFL!! Backups should be of the highest redundancy possible, so you actually have them when you need them.