My favourite titles tend to be the short, one shot type of works like Taniguchi's Haruka na Machi e, something mild that doesn't take too long. Manga artist here, I'm good with cg, visual novel-like cg is what I usually go for if you have seen it, but I can manage cel shading, as long as it is 2D, I have some pictures on imageboards if you want to check them out too, I don't have high rates since I always charge based on the job done, only rarely work on a time-based schedule (such as when there's a deadline), if it's coloured it will take longer of course, once I finish the lineart you can pay half the price and then the rest when it's finished.
Estimated completion time depends on the amount of detail, resolution and other factors, but normally I can get a simple sketch done in about two days.
Prices range from:
10USD = a simple sketch for character design or storyboards, no shading
20USD = single page B&W with halftone, cel shading
35USD = single page coloured no background up to 3 chars multilayered cg shading
45USD = single page coloured with detailed background multilayered shading