For DVD duplication runs under 100, with 7mm slim cases and inserts, I charge $10 each. For CD runs under 100, with CD jewel cases and inserts, I charge $6 each; for insertion in 7mm slim cases with inserts, $8.
There's my time, ink, supplies, packaging, shipping and handling involved, along with costs of the disks and cases, plus dealing with THEIR incorrectly sized or otherwise problematic insert art, or having to develop graphics for them.
Unlike many small run duplicators out there I do not charge "set up" fees, or other nickle and dime charges. But I do have to make some reasonable profit for my time, skills and the grunt work involved. This is why big houses won't take on small runs without charging extremely high premiums AND stacking "set up" fees on top of that, plus anything else they can come up with to up the bottom line.
If a client wants a couple of copies, they'll pay $15 for either DVD or CD, and that includes mailing. Rush for overnight duplication needs is $50; and they can save shipping costs by picking up and dropping off.
I have price breaks for jobs over 100 units, but they're not going to be as cheap as some on-line stores or other shops might let them go. I simply have MORE costs and LESS time as an individual independent professional video services provider, therefore large orders are not my focus, but I won't turn them down if my price is met.