One of my clients is trying to do some weird things with shipping.

He wants to calculate a flat rate of $4 for a quantity of 5 widgets or fewer, and then add $1.50 per block of 5 widgets (ie, if someone orders 8, it should charge $5.50, or if the quantity is 12, then $7). This is only for one type of product, though, but he’s got multiple items of that product type, entered in as separate products.

I know, it’s a mess.

Is there any way to do this with shipping zones or something similar?