Price for the variants

We'll need more information to be able to answer.
Are you talking about different products or only one product ?
Can I purchase 2 pieces of product A, and 2 pieces of product B ?
Or it must be at least 3 pieces of product A, and 3 pieces of product B ?

Hi,

What you can do is add many prices for the product:
Each price can have a "minimum quantity" and a "unit price".
In the cart, the unit price of the product will be : the unit price with the lowest amount among the prices matching the "minimum quantity" based on the quantity of the product in the cart.
Then, it will be multiplied by the quantity of the product to get total price.
So the issue with that is that if you want a fixed increment for the price while the first unit has a different amount than the increment, it would require calculating the unit price for each quantity and adding a corresponding price to the product.

So either you're ok with having many prices entered and either restricting the max amount of the product in the order, or having a price increasing not in increments but proportionally to the quantity of the product in the cart.
Or it requires the development of a plugin to calculate the total differently and use an increment from a custom product field.