The pricing for Storj V2 was $1.5/TB of used space per month online and $30/TB of downloads by customers per month.
The price was set at that level because we had to store a high number of mirrors. The renter pays $15 per month to upload 1 TB of their data. With Reed-Solomon erasure encoding, the total size of data stored inflated to 2 TB and the resulting shards were stored on 6 farmers. At the end, 12 times as much space as the original file size was actually occupied on the farmers storing all the shards and mirrors. Storj Labs also needs to earn some money to pay their developers and for infrastructure maintenance costs.
For the V3 network, we hope to be able to provide higher payouts to storage node operators, and a lower price for the renters for storing their files.
At the moment, the storage node in v3 alpha/beta will be paid $1.5/TB of used space, $10/TB of egress (outgoing traffic) for repairs and audits and $20/TB of egress downloads.
You can use the Storage Node Payout Estimator to get an idea.