You wont really know if users are gonna purchase your work my simple answer: would be when your ready start getting your work out there create variation high quality designs and put them inside your portfolio, if you put your art out there people will notice your work and see if they can commission you. Take this with a grain of salt.
Your 3 pieces of work are getting there I would try creating more pieces to put inside your portfolio to get commission from the little designs you have at the moment. I wouldn’t strive into doing commissions just for making a little robux if your not ready, no one will buy from you if you don’t get your artwork out there.
My simple recommendation would be keep creating more work post them in active community’s, take the time to practice and learn different things what are ways to improve my work. First you need a portfolio to show your artwork to users and clients. I would try making more pieces of work before getting commission from the work you have now.
Looks pretty good! Even though I’m terrible with Blender, I would prefer to do my own (and well I haven’t got any requests for commissions so far so it might take a while to even get a request).
It all looks very unprofessional yet, and it lacks something. Definetly get more creative and you are using these wild fonts which really don’t fit, I also don’t like the shadowing and over complexity on the text, other than that, I think the lighting could be worked on.