Pricing products by options

I need to price a number of products based the size of the product.

I have done a search in extensions and see there are some paid extensions which allow pricing for different options but show them as ' +£x.xx or -£x.xx).
For customer clarity I would prefer to show the total price for each option when the customer views them.

Does anyone know if this is possible in the standard package, and if so how - or if there is an extension which does this.

Thanks

Sorted.

I found a solution.

Could you share your solution?

We used this extension

You to set options for the product which show on the product page, and as a customer makes a selection the price on the page updates to the price that will be charged depending on the option chosen.