Commerce: Batch Good = Good A + Good B, adjusting stock

[Meddysong]

I don't think it's possible to do this but if I'm wrong, please show me how to pull it off :)

Sometimes I might want to batch products together, making it possible for people to buy Good A and Good B as a single unit, say a two-volume set of books or an attempt to shift stock at a cheaper price than the individual units would cost sold separaretely.

In this instance, I'd like to create a product which is Good A and Good B together. I expect that every respect of creating this new product would be as with any other, only I'd be able to indicate that it consists of one of Good A and one of Good B. Upon selling one of these Batch Goods, the stock numbers for Batch Good, Good A and Good B would all reduce by 1. It shouldn't be the case that there are more of Batch Good on offer than there are the items of which it comprises.

If I were to set things up as they stand now, there's a risk that I could have in the market something for sale which I can't actually fulfill because even though I might have indicated having x of Good A (or Batch Good) for sale, I might actually have sold some of Batch Good (or Good A) such that my stock levels aren't accurate. Then the order comes in because the site is showing the product as available and I find that I actually don't have any left because the stock price won't have adjusted. It would be nice to be able to work around this concern (assuming it isn't possible to do so already).