What price range should I expect for Storj and will it be permanent too?
Prices for storing files on the Storj network will be dictated by the market (supply vs demand). Most likely they will be waaay lower than Dropbox rates.
Keep in mind that price for space is on Storj is one thing and the value of SJCX is another. Both will be controlled by the market. the valuation of SJCX will be factor into the cost of space on the Storj network.
So they're not tied together? how are they separated?
The cost of space on the Storj network will depend on the availability of space. If everyone and their neighbor is providing but no one is really consuming it , the price will be cheap. If there is more demand that space available it will be expensive. Supply and demand. The thing here is that the supply is drive space.
A separate market will exist for the SJCX in the same way. I might have lots of SJCX and want to hoard it, thus taking it out of circulation. If many people do this the available supply with diminish thus creating an upward movement in the valuation of SJCX. If then at a later time there is a flood of SJCX back in to the market the valuation will drop.
Until such time as there is a market directly between USD (or any other currency) and SJCX, BTC valuation will matter. So the valuation will be USD (or other currency) -> BTC -> SJCX -> Cost of Drive space. Each node of that map can fluctuate affecting the cost.
SJCX and the price of drive space are more connected than say BTC or USD to the price of drive space, but they are all disconnected.