In most categories you pack the item. Here you pack the packaging, and that changes the delivery arithmetic.
What decides it
Volume, not weight. A boxed collectible is light and large, and most couriers price on size as well as weight. A collectible box inside a shipping carton with filling all round is a noticeably bigger parcel than the box alone, and that is the parcel you must quote for. Packing boxed collectibles.
Measure the outer carton before the show. This is the category where sellers most often quote for the item and pay for the box.
The four options
Courier — the default, with the outer carton costed properly. Your own delivery — good locally, especially for large boxed pieces. Pickup — the honest answer for big display pieces and for bulk lots. Buyer arranges — for large collections.
Combining wins
Boxed pieces combine badly — two boxes is two boxes' worth of volume. Loose pieces combine beautifully.
Combining is on by default and you set what each later win adds. For a boxed category, setting that figure thoughtfully matters more than it does anywhere else.
When collection is the honest answer
For large boxed items, display pieces and anything where the carton would be enormous. Agreed before bidding with a collect-by window. How pickup works.
Questions people ask
Can I ship in the collectible box?
Not if the box is part of the value. Ask the buyer in writing if you think otherwise, and keep the message.
Should I offer free delivery?
Only costed on the outer carton, not the item.
What about very large pieces?
Collection, said in the listing before bidding starts.
More: setting up delivery, selling toys.