Nice to see this question, I had once struggled a bit on this until finally I figured out a solution which I thought will have to be built bespoke, but thankfully there was a similar module that was available for the job.
This module changes the way pricing of configurable products works in Magento.
When enabled, a configurable product's own price is not used and the price used will be that of the matching associated product.
This gives site owners direct control to set the price of every configuration of a product, while still giving users the flexibility they usually get with configurable products. (There's no more having to set rules such as: +20% for blue, -£10 for small, +15% for leather. You just price the underlying small-blue-leather product at £199.99 and that's what the user pays.)
This change has two effects on the behaviour of a Magento site:
- When an attempt is made to add a configurable product to the basket/cart, the matching associated simple product is added instead.
- Configurable product prices are shown with "Price from:" followed by the lowest price that this product can be configured to. (Once configurable options have been chosen by the user and the specific product price is known, the 'Price from:' text disappears)
More details are available here. And is free for use I believe :)
https://github.com/organicinternet/magento-configurable-simple