-It will cost you one transaction to create an Alias (this is your "identity" or "store name"). Your identity will last for one year unless you pay much more for it to last longer (this is done to prevent name squatting such as is currently done with Domain Names).

-It will cost you another 0.017 SYS to list an item on Blockmarket which will also last 1 year.

... As far as Aliases...
Is there any possibility to extend / continue the name of my Alias just before the end of the 1st year for the same price?
It would be very important to have the same Alias all the time but for reasonable price.