Where can I find and how much does it cost to order a picture for Roblox mode?

Okay, I have an Anime Mode coming out soon, and then a question came up. Where to find a good designer to make a picture for the mode, and maybe a group. And how much it would cost, here are examples of how it should be approximately: (if anything these pictures I took from other modes, this is just an example)

People usually charge 5k to 15k robux but honestly not sure