The webpage is a little clunky but it works most of the time. Note the current Grid Stats. Statistics were up to date as of 3:00 PM Mountain Time USA on Sunday 25 Jan. 2015.
Here are the Standard Grid Services, also known as Free Services.
It's easy to join the Grid and get started.
You can also load up your avatar with hundreds of free items before your first rez inworld.
You may buy Game Tokens or GT if you wish. GT is similar to Lindens in SL.
You'll be able to find plenty of Free Items in ATEK so it isn't necessary now, but as the population grows there will be a greater demand for avatar customization and various accessories, buildings, vehicles, etc. ATEK is two months old and stores for avatar skin and clothing are popping up here and there.