3D printed figures is becoming more and more common today but SLA/DLP and other resin printers are very expensive so that's why these printed figures are expensive.
It's not a case of a 3D printed mould which is poured with resin - every figure is printed!
But if you're artistic enough to 3D sculpt a figure it's not so expensive to have one printed for you on a professional printer, but expect to pay £50-60 for a small figure in the cheapest material.
I've sculpted an more or less exact replica of the kugelpazer the Russians got on display, welded up, because it's unobtanium since it run out of production.
It's not very big at all in 1/35 scale but due to it's design it's a complicated print and the cost was almost £200 - which I'm not prepared to pay!!!
My brother is buying a new 3D printer, much better than my gen 2 Prusa Mendel I built many years ago and he will print the kugelpanzer on his eventually and I'll use putty and sanding to create what I want - much cheaper than £200! (especially since my brother is paying for the plastic filament... hehe...)
I'm looking forward to see your new figures painted!