If having a website is important to you, you can go to http://www.rspropmasters.com
Much better quality and accuracy. Or pick one from our vetted vendors list and send them an email or PM here on the forum.
All Santroopers have kidney notches. It's the same armour as stormtroopers's in ANH.
Here's a picture of the original sandtrooper armour that Simon of RS Props owns, before it was cleaned up.
Even a single 3D print of something this large in high quality will be very expensive to print, then mould, then cast.
If you factor in wages x man hours for all the workers involved. Sure, no problem.
Maybe the master suit was 3D printed, but that was then moulded and cast in urethane for the actors. No one is crazy enough to 3D print 50+ complete suits. That's just a waste of both time and money.
Why go through the effort to make your own moulds, build a vec-form and buy the plastic, then find it's hard and costly and didn't turn out very well, when you can buy a finished kit from someone who know's what they are doing, for much less?