Limiting # of products in group

I was surprised to not find any threads dealing with this issue. If I missed one, please let me know.

We need to limit the number of products of a particular type that a customer can add to an order. For instance, we have some super large products, whereby we can only deliver a maximum of 2 per order. However, there are multiple products of this type.

So, I was wondering if it were possible to limit the number of a group of products per order. Perhaps, I could create a new product type with these products? And somehow limit the number of that product type in the order? Just guessing, any help is well appreciated.

I'd like to, in the long run, charge a fee per each additional of these products added to the cart. So, if the limit is 2, the 3rd in the cart will add a $5 charge to the order. I'm guessing this isn't currently doable, so I'm fine with just limiting it to 2 per order.

Currently, limits are done on a per Product basis and not on a per group basis ...

You would need to customize the code for something like that ...