I think it's important to remember that Midjourney does not allow for you to pay less than $10 per month. And Dalle-2 doesn't allow an expense less than $15. The minimum amount of money you can pay on describe.photo is $0.20, making getting images on demand. For the person that only wants to generate a few images and not 200, the $0.20 will always be cheaper than $10 min but for $0.05 / render.