Industry rates for custom DC design

Hello everyone! I am wondering what the current price range is for custom DC design. I have accumulated a library of custom DC’s and I am considering selling them, but have no frame of reference regarding a fair price for this sort of thing. I figure it depends heavily on the quality and complexity, just looking to establish a wide range for this type of CAD work. Thanks for any input!

p.s. if you don’t want to post publicly about rates you can PM me.