Either way, shipping cost goes up when an item is INF'd. I'd imagine the system prioritizes stores that are in the closest shipping zone to the customer, so even if it's a one item order, moving it to a further away store will increase the actual cost of shipping that package.It depends on how we allocate our cost. I would suspect the shipping process begins with the order drop. Most likely we allocate cost/minutes since this appears to be the units of time we're measured on. This would explain the emphasis on order picking time and then packing.Once the order is processed and waiting for p/u, the cost meter stops and does not restart until the package is shipped or returned to stock. The lag times for p/u and/or cancelled orders should fall under another cost category all together.
The actual cost of shipping via a carrier is created upon the trailer leaving the dock (FOB Shipping Point). It doesn't matter if it is a selected carrier or a Target Trailer, we pay for it.
If it's a multi item order, you've now created an additional package coming from further away for an item that would, most of the time, just added a little weight to the original package. I'm actually a bit surprised the system doesn't occasionally cancel out a whole order if there are a couple of INFs, because of the possibility of creating multiple extra packages if the next store doesn't have both cancelled items.
And that's just the actual shipping cost. Doesn't even consider the labor of having the first person searching for it, then the duplicate effort put in at the second store to pick/pack it.
There's also inconvenience to the guest. I ordered an item during Christmas with rush shipping that was supposed to arrive the next day. After bouncing around due to INFs, it finally shipped 2 days later from across the country. So it took 9 days to arrive instead of coming the next day. That's probably one of the more extreme cases, but it does happen.