Great work, especially on the metals and stones.
You can improve on skin, fabric and variations of matte vs. glossy finishes.

The website is a bit standard and can use some more character.
I don't see the prices but I imagine around EUR 150 is a reasonable price for a 6" sculpture.

Look for local designers on 3D hubs to collaborate and have them 3D design and print the models.

Congratulations with starting the business!
Wishing you a lot of success.