Using the Commerce Kickstart distribution to sell non-standard products
Not really an answer, but only my point of view.

I would create a dummy item without price and add the calculated price to the carrier fees.
You can trigger almost every action you need from Rules.


Add FOO item to cart.
Add the transport fee to the order.


This rules are already there in Kickstart, you will only have to tune the Carrier fee calculation rules to fit your use case.
Of course I don't think Kickstart is designed with selling services in mind but I don't think you are going to find any major problem in going this way. Think of a store with only one product that ships worlwide with different transport fees. The carrier can well be a variation type of your product.

My 2 cents.