Wow! I really like the first one. ^_^ Your shading and coloring is fantastic. I wish I could draw like you. ; o;
Anyways, if you're selling the gajinkas as adoptables, maybe 300-500k? If you're selling them as custom commissions, perhaps 1mil+ TU?
The human is pretty good, although I like the gajinka better. X3 Maybe the humans could sell for around the same price as the gajinkas, or maybe a little bit less.
It depends on what people would be willing to pay if you started a thread. I'd be willing to pay around 1-2 mil for these. It also depends on the effort put into these, although more so what others will pay for your art.
Good luck selling! <3