I've recently gotten a customer interested in a character sheet commission. Their interest is in lineart, because while they want the picture colored, they've told me they could color the lines themselves. Obviously a picture with colors, even flat ones, is more expensive than just lineart, so I understand the reason for the request.
For commissions, I don't send the original sai/psd file: I send my clients png files, but admittedly, my lineart is very clean, so it wouldn't be hard to either fill in the blanks or use certain techniques in photoshop to make a layer out of it. I do offer sending over the original file for an extra fee, and of course I'd expect the client to make minor modifications to the piece if they bought the original file, but I guess I never thought I'd be asked to send in a sketch or lineart just so the customer could finish the picture. I'm not sure I'm comfortable with the message it would send, either: why would anyone buy my flats, if they can buy my lineart and the original file, and finish the job themselves for a lower price? Not to mention the obvious self-doubt that goes on there. Are my flats that bad? Are my prices too high?
I've worked with this customer before, for a simple sketch. Those lines are messier than my lineart, but back then, they asked if they could lay some flats on the sketch to test it out, and I said yes. That might've been a mistake on my end, but well, it's a sketch, not on par with my more polished stuff, so I didn't really think much of it.
So first, I wanted to know the community's thoughts on accepting lower-tier commissions when the customer has admitted they'll be heavily modifying (read: finishing) the picture themselves. Perhaps I'm being overzealous without realizing it. Then second, depending on that first question, how I should deal with the customer (good person, not pushy or anything) about this.
Thanks in advance to anyone reading this, and any advice that might get offered.