Best way to set prices

[Guest]

I have several items which come in 3-4 sizes.

I tried to use attributes: assigning, small, medium, large etc.

I then list the price -- The dropdown lists the sizes with prices (+20.00)

then when ordered it adds 20.00 to the base price.

That works, but is a bit confusing.

What would the best way be, to list size choices with the actual price listed in the dropdown --

thanks,