In my case I need to sell the newspaper spots. Each of them has a different size and layout.

So instead of creating a product instance for each of them I'd like to provide an option for a user to choose from attribute options and calculate the price on selection.

Is it possible under the Attributes > Text Options / data-entry forms > Add/Edit Option(data-entry form control)
to multiply the price like

Instead of + use *

16×10 - Page 2 Solus=+160
16×10 - Page 2 Solus=*160