Hello there!
I'm a graphic designer who has been using Photoshop for almost 7 years now, so tasks like removing backgrounds are part of my everyday job.
Depending on the picture it might take more or less, but in general, it doesn't take me more than a few minutes to remove backgrounds from pictures with high quality.
I've worked on background removals before here on freelancer, feel free to check my profile and see the reviews.
If there's any more information that I need to be aware of before starting, let me know.
-Jorge Miquilena