All valid concerns, and I definitely have an understanding of the difference between launching a game now and launching one five years ago. The thing we keep coming back to is this: If the game is deemed "good," people truly enjoy it, and those points are being translated to those potentially interested, the $5 difference isn't going to be a big picture issue. I just can't see it. However, the safety net the $20 price provides if the game doesn't launch well could keep us better afloat as a company moving forward.
When we released Bionic Dues for $10 to a poor launch, rallying was much more difficult. We actually received quite a bit of press for the game at launch, despite the perception that we didn't spend anytime marketing it at all (I'm still not exactly sure what ultimately went wrong, though looking back I regret not gently getting the word out months in advance like we have with TLF). The game just didn't sell much at all, for whatever reason. Not including bundle inclusions, we've discounted the game twice on Steam since (iirc); and though the game's player pool has tripled directly because of those sales, the amount we earn per purchase just doesn't cut it in terms of what we're looking to earn during these types of promotions.
Skyward Collapse is even worse at $5. Discounting it 50% means that we are making less than $2 a copy. $20 means you can discount down to $15, $12.50, $10, $7.50, $5, and $4 over the long haul -- that gives us a lot more opportunity at featured and/or weekly promotions that will actually move the needle. The diminishing returns of discounting a $5-$15 game repeatedly at 75% off is much more apparent. You just get lost in a sea of games at some point, unless you're a DayZ, Starbound, etc. Baseline sales for the AI War collection (at $17) is the only product that sells day-in and day-out for us at regular price. We really need TLF to fall into that category as well (regardless of how it launches, the money we earn from it will almost certainly run out at some point) -- otherwise we're going to be scrambling here for the foreseeable future.
To put all of that in another way, I think we've been bit on our behind a few times by going with a price the market is telling us to go with, instead of the one we feel is actually justified. This may well turn out to be the wrong decision, but everything taken into account, it feels right. I know that's vague, but that's just the hunch I have.
Also, does it make any difference to know that the launch week discount we're planning is 25% off? So $15 will be the "launch price," it just happens to be a temporary one.