"How much is too much?" is a relative question.
$2.00 to $6.00 for good to VERY good blanks.
$8.00 - $10.00 for GREAT wood and synthetic design.
$15 - $30 for custom that is also very eye appealing, extremely unique, or one of a kind rare. One of my personal observations is that once blanks hit around $10.00 to $12.00, orders drop to special order. Exceptions are the "Cross", "Stars and Stripes", "Piano", and snake skins. Yours might fit in here too. It sure sounds good.
Problem is, we often think of our own creations as more appealing than it actually is and want to charge for it according to our own personal feelings.
Example:
Click here for a view of one of my pens. The amount of time it took to make the blank was about about 3 hours. When I was doing graduate work in the late '70s, I made $12.00 an hour loading and unloading trucks to provide for my growing family. Using that as a standard for today, I should at least charge $36.00 for time alone. Would anyone be willing to pay for the time alone for what I have in it?
IF I wanted to make even a small profit, I would have to charge $45 - $50.00 for it. I don't think anyone will pay what it is worth for me to make one. And I still owe a blank to one fellow for some help, when I get some time to get into the shop.
To really sell something, the price has to be reasonable and that usually comes from mass production, which I have not figured out yet for my stripe blank.