I'm not a businessman and don't have any data to back up the following theories, but this aims to at least present a possible (but probably far from optimized) way to offer both digital downloads AND physical goods, while mostly maintaining the monetary advantage of digital only.
First, offer digital downloads. No reason not to.
Then, you could offer a physical copy of the game. Box, manual, all that stuff. But you could charge a higher price (something like $5-10 more, USD), to cover the cost of production and materials and all that stuff. Also a shipping fee, of course, if you'd sell it online (instead of, or in addition to stores).
Those who just care about the game can buy the digital download, those of us who value physical products have our desires met. To compensate for the availability of digital download, produce a minimum of the actual boxed game. The biggest problem here is finding the "sweet spot" between producing too few and having it be scarce (leading to many players who want a physical copy not getting it), and too many, leading to them sitting in a warehouse, unsold.
Of course, the idea is far from optimal, since I'm sure it's even harder than I would imagine to set up the physical production and then distribution of a product (especially if Larian does it themselves, if that would even be possible in the first place). Still, it IS a way to satisfy all parties to some extent.
