Has anyone set up a 'by - category' type shipping plugin in exp:resso store?
I want to allow the client to use the category list to manage their own categories for products, but at the same time put in a flat rate for shipping per category.
For example, if a category falls under the category of books, the shipping is $4. If it is something small like seeds, shipping is $1, etc etc. If they pick one of each, the larger is taken as the final shipping price.
I am looking at the: per_item_rate, per_weight_rate fields in the store tables and I am thinking of adding a: per_category_rate table, but don't want to modify core stuff, only extending what is there for easy upgrades.
So taking the default shipping plugin - would it be best to start from this and build upon it, making change to the database fields and logic within it?
Or, would it be better to pull from a category group, and use a custom shipping field for the category, and roll your own plugin for shipping this way?
Any points in the right direction will ensure I don't go too far down one route when another is the best practice or more flexible way of going about it.