Stockable variant with additional charge

[aarushi2001]

I really need some help and hope someone will be kind enough to help me. This is what I am trying to do:
I have a product that is available in different colors. I want to charge additional price for each color. For example a white t-shirt (default) would cost $10 and a black t-shirt would cost $15.

Under the custom field, if I use cart, then I was successful enough to show different options and update the price. However, I also want to update the image when a user selects white.blue or black. After reading forum topics, I started playing with stockable variants. My images are getting updated but my prices are wrong. By default, the price is showing up as $15 and if I select any color option, then nothing happens. As per tutorials I read online, I have added $5 under the additional charge next to the "black" color.

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