And if you work in a big company, who knows! They might already have a group license you can you.
As for me, you can pry my Emacs from my cold, dead fingers.
Step 1. Remove nag message. Step 2. Release to the world. Day 3. Tonnes of people jump to non-nag version and never pay.
The plugin system and API is available for those that wish to complement or extend the editor. Making the code available directly harms their ability to make money and their ability to continue to invest time and money building the product.
I do understand the concern though, but for a lot of people (myself included) ST is a better solution than a non-proprietary solution.
Perhaps the wrong place for flaimbait.... I apologize ahead of time!
I would have bought it if it was $29 and proprietary OR $70 opensource donation ware or $49 proprietary with 3 free version upgrades. That's my comfort feel around editors - YFMV of course.
If were purely a Python, PHP or otherwise Web developer, I haven't found a whole lot in ST2 that you can't get in Notepad++ (even without additional plugins).
The great news here is you can test drive Sublime Text to definitively decide if the price is right. For me, it was, but I would also caution against jumping on it just because a lot of people do/have. There are developers who wouldn't necessarily benefit from this over the alternative(s).
Otherwise just deal with unobtrusive nagging until you decide it is worth it