Depending on how complex you can get, I would personally pay 70-100 USD [ and more if I wasn't poor xD ]
Are futuristic pieces out of the question?
Like ship interiors and such?

No, it can be anything, any genre of fantasy, si-fi and others, just I do not have enough examples yet, so I can do both interior and exterior. Thank you very much for the comment, it's really important thing!^^

Awesome!
Depending on the price and if you open them I may be looking to get some ship/room designs done for certain sci-fi characters!

It will be wonderful! I will write the announcement when I'm ready.

These types of art pieces are always wonderful to see because of the feel the environment gives to the viewer, even without characters and can leave a great story to tell from it! I've scene complex environment pieces go for between $60 - $100+ obviously depending on how complex it is.

I would love to commission one of these if I had the funds! You did a wonderful job on the two examples you gave!

You're right! However, the customer will still be able to add to the drawing of your character, although the main part will occupy the environment.
Thank you for your opinion, I'm really glad to hear that my works are interesting to people!

I haven't seen many, if any, folk doing environment commissions. I think the idea sounds Really awesome! I have environments/worlds some of my characters inhabit that no one has seen and written word can only do so much so the idea of commissioning a piece that could provide a visual for those would be incredible :)

One specifically for a game campaign I'm participating in where my character hails from a scifi city that has been built up and up and up. It has tiers, the ground/lowest tier being the slums and the sky tier where the wealthy and famous reside at the very top among the clouds.

Thanks for the comment! And really I just now realized that I have a great advantage, because in principle, most artists specialize in drawing characters, not on the environment.
I will be happy to implement your ideas, as she planned to draw a couple of illustrations based on the text!
Of course at first I will take only for not very complex orders, gradually complicating them!

Most definitely! I love creating environments in my head but I can never express how they look to others so environment commissions would be an amazing thing :)

That sounds like a great plan :)

I hope to help you with that!^^

I'll look forward to that :)