Above the free retrieval quota (5% of your storage per month), pricing is based entirely on your peak hourly retrieval rate for the month, billed at $7.20 x [peak rate measured in GB/hr].

So for example, if you retrieve 100 GB in one hour, that's $720. If you retrieve 10 TB at the rate of 100 GB/hr for 100 hours, that's also $720.

Translated into bandwidth (assuming you're pulling at this rate for at least an hour), it's about $3 per Mbps. So if you limit your retrieval to 10 Mbps, you'll pay $30, regardless of how much data you retrieve. This makes it fairly easy to cap your expenditure, if you have a client that can stagger its requests appropriately (you need to throttle the Glacier retrieval requests, possibly using Glacier's range requests if you have very large files, not throttle at the network level).

Here's my last bill:

    $0.010 per GB / month - Storage 	2112.146 GB-Mo 	21.12
    $0.050 per 1,000 Requests 	40,447 Requests 	2.02

My last "restoration" was actually setting up a new iMac at a remote site involved downloading ~60GB over ~20hour and cost me about $30