I don't know how they'll do it either, but looking at the features on the product page at DAZ between Core (free) and Advanced (pay for) it definately looks like the advanced lighting features are pay for.
The Studio features page ( http://www.daz3d.com/i/software/daz_studio3/features?_m=d ) seems to back it up too.

Your swimsuits and such do look good.