Your see more then one thread now over at DAZ on checkout troubles and on the getting  "One Free Masters Series Product!"
Was said do not copy and paste the coupon code but to type it out works.

But I no longer have the coupon code so still things are not working right.
Where did it go?

Plus there is the Platinum Club that cost but you get to buy things for even less and they have lots and lots of things for $1.99 and you get a $5 Voucher FREE Every Month.
http://www.daz3d.com/i.x/platinum/0/-/?

So a great deal for those who spend money all the time buying.

But I say there is lots of great free software and free version of the paid version that are the same or limited in some way. Some are limited more then others and some may have a nag that drive you crazy were other you may not even know your using a limited free version. Like Terragen I think the free version your only limited in the size of the image you make.