Cost wise, Larian would make a lot more from selling physical copies on their site rather than selling digital through Steam or GOG. They both take a huge cut. A printed box, DVD's and perhaps a printed map will barely cost $2 and shipping would be media mail so only about $2 more. How long does it take someone to take a automatically printed sticker and plop it on a box then put said box on the outgoing mail table?
How much does Steam pilfer these days? 30%-50%? So for every $50 sale Larian only makes about $25-$37 vs. closer to $45 if they printed and sold their own physical copies.
Industry standard for digital games sales is ~30% (Source:
https://www.quora.com/Valve-company-What-percentage-does-Steam-keep-from-sales). Some estimates are closer to 40%, so let's take that and assume a take-home of ~60%.
This is a larger cut than Retail, but Retail includes other costs:
http://kotaku.com/5479698/what-your-60-really-buys. Rough estimate there is take home ranges from about 50%-60%.
Most likely, it's not really cheaper to operate in Retail vs. Steam. In fact, if you do all sales online you don't have to deal with supply chain and manufacturing which lets you run on a leaner staff which saves the company money as well. Integration with a platform like Steam is likely cheaper in the long run.
Only real question is whether they are missing out on money by not going retail. The answer is probably yes, but they've made it clear that the extra operational cost is not worth it to them; they're focused on the game.
