Yesterday I had lunch with a vintage car friend. He opened his trunk to show me a wheel cover for a 1974 aluminum wheel and he was happy he got it for just $27. He bought 4 of them.
I could have drawn it up in an hour, printed it in another 40 minutes and it would have cost me about 50 cents.
That's just consumables. Add the cost of your time at a very conservative $75.00/hr and you're at $75.50. What should you charge for production time on the printer? $25.00? You're over $100.00. Then, if you're planning on being a viable business concern, there's markup for profit.