I'm looking for an ecommerce platform that can support very customisable products. The site would need to ask the customer various questions (possibly even asking further questions based on their answers so far) and the cost would be determined by their answers. But it wouldn't be as simple as as different answers having a different cost. For example, customers might be able type in different dimensions, which would need to multiplied together to calculate a volume, then rounded up to an available size to generate a cost.
At the moment I'm thinking that I might need to create a bespoke module for one of Drupal's ecommerce solutions. But I'd like to find out whether there are any alternatives to consider...