I have no doubt you could sell some commissions, you clearly have the skill. For the two character pieces I see in your gallery, I suspect you could get upwards of $100 for one, if you can get enough interest. Pricing is hard, and really the only way to know what people will pay is to try selling commissions.

$70 per character seems like a fair price to me ^^

A good way to gauge a general price range might be to post a few YCHs. Start at something like $25 or per slot and see what people are willing to bid.

You should set them against how long it takes you to do a particular quality level. Color sketches, full scene paints, one or two characters. How long do these take you to do? Then take those hours and set a wage for yourself.

I know this is sorta a non-answer to your question, but I see lots of artists burning themselves out and long term undervaluing themselves by spending 20 hours on something and charging $100.

This is easily the correct answer.
Undervaluing yourself is exceptionally easy to do, and it's a lot harder to raise prices once people get used to a certain pricepoint.

A base price I commonly see is around $60-70 per character, with adjustments for complexity, backgrounds, and so on...
And honestly, you could very easily charge that from the art you've done. It's honestly amazing. <3