Looking for advice for how to set up products

[[n]atalie]

The products are pillows, and they have 1 attribute: firmness.
For example:

Standard Size Down Filled Pillow
Soft = $100
Medium = $125
Firm = $150

I tried doing this with generic child attributes:
parent = "Standard Size Down Filled Pillow"
child = "Medium    $125"
because I needed price to show up in the drop down, but then the parent is still in the dropdown and people shouldn't be able to add the parent to their cart.

Now I think a Cart Variant custom field is the right choice, but I need the prices to display logically. In VM 1 you could set price for attributes to "=125" which would change the price, instead of adding or subtracting to change it, but it doesn't seem to work in in VM 2.

I just need some advice from someone more experienced with VM about the best way to do this?

Any help would be really appreciated.