Hi Robert,

The categorization and presentation of the products is usually driven by the product documents. See the difference and connection in the E-commerce Guide article about products.

The upcoming version 7.0 goes in the direction of bringing the product document and actual E-commerce products together to make the management easier. I would recommend to check the blogpost Product UI and management in 7.0

Currently, lot of the categorization can be controlled by appropriately wide set of Product document types (Cars, Airplanes), The ranges can then be represented by the pages structure in the content tree.
Together with Document Categories it can offer lot of options for products listing and presentation.
In the administration interface, things could be improved for particular purposes by customizations.

Product options can be globally applicable (like general colours), or bound to the product specifics (which would be needed for our Inventory feature).

The pricing model will require to have the custom price and discount fields for regions, lot of actions can be customized and so the maintenance doesn't have to be a nightmare.
The key thing is to know the optimal and best described scenario of the different prices management that you plan to implement. With more details we can suggest the best way, otherwise it's just talking around (which could be useful -I'm not saying it couldn't :)
Any further details (here in forums or via the support email) will be appreciated and will allow us to answer more accurately.
Thank you in advance.

Should you need any additional details, please feel free to ask.

Kind regards,
Zdenek