For data storage, you need error encoding. Sia does that, but you pay for it. So for 1TB of data, you upload 2TB to the network (that's how Sia is configured) and at the current $2.02/TB per month, that's $4.04/TB, which is more expensive than Glacier. Glacier charges funny for downloads but Sia charges for downloads too.
I assume that if you wanted to store ~2.5TB like we're talking about, you'd be paying more than $4/TB, because 2.5TB is 10% of the total of all data currently stored in Sia, currently 24.5 TB. (By comparison the major cloud providers are undoubtedly in the exabyte range of actual data stored. Or for another comparison, you could comfortably hold 24.5 TB of storage media in one hand.)
Sia promises to be cheap because you're using unused bytes in hard drives that people already bought, but that's exactly what Amazon, Google, and Microsoft are already doing, except their data centers are built in places where the electricity costs less than what you're paying. Plus they don't charge you extra for data redundancy.
In that case, Sia provides an avenue for an new company with access to cheap electricity to compete with Amazon, Google, and Microsoft without investing a cent in marketing or product. They will just plug in and start receiving payments, and strengthen the network and lower the price in the process.
Another cool thing is Sia lets hosters set their storage and bandwidth prices, so specialized hosts will likely pop up. For example one host might use tape drives, set cheap storage cost and expensive bandwidth cost. Clients can prioritize as desired. SSD servers with good peering can do the opposite.
The real interesting part will be when you can create one-time-use URLs to pass out, which connect directly to the network - effectively turning it into a distributed CDN.
The $2 / TB / Mo we've traditionally advertised as our price included 3x redundancy. The math we've done on reliability suggests that really you only need about 1.5x redundancy once you are using 96 hosts for storage.
The network prices today are less friendly, though that's primarily due to market confusion. The siacoin price has doubled 6 times in 6 months, and there's no mechanic to automatically re-adjust host prices and the coin price moves around. So hosts are all currently advertising storage at these hugely inflated rates, and newcomers to Sia don't realize that these aren't really competitive prices.
Though, I will assert that even at our current prices it's not price that's the primary barrier to adoption. It's some combination of usability, and uncertainty. Sia is pretty hard to set up (it's around 8 steps, with two of those steps taking over an hour to complete), and a lot of people are not certain that Sia is truly stable enough to hold their data.
You can't compare to Glacier. S3 is a more comparable product. And obviously redundancy is already in the price, or did you think there's no redundancy?
From what I understand, your client does the error encoding and pays for raw data storage on the network, rather than trusting the network to do error encoding. You can configure the encoding to whatever you want, you just end up paying more for more redundant encodings.
For data storage, you need error encoding. Sia does that, but you pay for it. So for 1TB of data, you upload 2TB to the network (that's how Sia is configured) and at the current $2.02/TB per month, that's $4.04/TB, which is more expensive than Glacier. Glacier charges funny for downloads but Sia charges for downloads too.
I assume that if you wanted to store ~2.5TB like we're talking about, you'd be paying more than $4/TB, because 2.5TB is 10% of the total of all data currently stored in Sia, currently 24.5 TB. (By comparison the major cloud providers are undoubtedly in the exabyte range of actual data stored. Or for another comparison, you could comfortably hold 24.5 TB of storage media in one hand.)
Sia promises to be cheap because you're using unused bytes in hard drives that people already bought, but that's exactly what Amazon, Google, and Microsoft are already doing, except their data centers are built in places where the electricity costs less than what you're paying. Plus they don't charge you extra for data redundancy.