Glacier have additional fees depending on how fast you retrieve the data. Honestly I'm not sure what they are because I've never had to use it, but my impression is that these fees could be quite high.
You will be surprised by a retrieval fee of 1000 / 4 * 720 * 0.01 = $1,800.
If you want to get your 1000 GB for free, you'd have to request no more than 69 MB per hour. It will take you about 20 months to get your data!
With Glacier, limit retrievals to less than 5% per month / 30 days / 24 hours = 0.007% of total data stored per hour to avoid these ugly surprises.
Source: http://aws.amazon.com/glacier/faqs/#How_much_data_can_I_retr...
In a disaster situation, a company is going to want hard drives sent to them next day. As others have mentioned, this isn't a money thing, it's a time issue. But it isn't available with Glacier (probably not with Google either...)