I think I saw these on eBay, don't remember the price you asked though.
Overall the army is quite nice as a table top standard if not slightly above.
Up close though, the individuals are lacking.
A key point of sloppy work is on the sergeant you did a close up of. The neck line is rough and looks unfinished.
I'm also not a huge fan of the flames, especially on the Vulkan model and the lava.
There is also an inconsistency between the display board and the armies bases. It's great that you've lined the lave flow up with the individual bases, but it creates a sudden change of colour, since you didn't paint the lava or the ground the same way on both.
But as I started with, it's a great table top army that'll catch anyone's eye!
Hope I didn't come off as to harsh, I just know your looking for top dollar on eBay and just making a few improvements for the next project will definitely net you big bucks!
Cheers!