Teen Vogue X Parsons: Choker Production Costs

An assignment I am working in for my Teen Vogue X Parsons course is to create a handmade necklace or accessory out of unordinary materials. I chose to use a ribbon as the base of the choker, 3 jewels, and painted 4 turquoise dots as well. With this, the next step was to focus on production costs. I defined my material costs for the materials I used to create the choker. The choker consists of a ribbon (measured to fit), three jewels, and four hand painted dots. I then added the costs to find a total of $8.99. It took me a half an hour to create the choker so I took the amount of time it took me to make it and multiplied it by the amount of money I would expect to make which is around $9/hour. Then, I simply added the total cost of materials by the total time to get $13.49. In order to get a profit of 20%, I took that $13.49 and multiplied it by .2 and got a profit of $2.69. In the end, the total cost and profit together is $16.18. However, I want to end up making a little bit more of a profit so the retail price would have to be a bit higher so I thought $20.00 would be a good retail price for the choker I created.