In the rest of the entry, he talks about comparing Braid to other comparable PC products, most of which run around $20. Simply put, if you'd pay $20 for World of Goo, wouldn't you then feel fine about paying the same amount for Braid? As someone who sits in the "World of Goo ain't all that" camp, an equal price seems pretty fair to me. But it's an interesting problem, as the markets and appropriate price points between the download services on consoles and their PC counterparts is quite different.
Either way, the PC version will be light on the DRM, which is nice. Here's what Blow had to say about that:
Where possible, the game will be released without DRM. Some online publishers include their own DRM as a matter of policy, and of those guys, I am only signing with the ones that have light and non-intrusive DRM. My goal is to give people a reasonable choice about where to get the game, and if they don’t like someone’s DRM or someone else’s launcher client, they can get it from whoever they like most.