I want to +1 every one of these posts! Well said.
$70 is NOT that much money, regardless of your situation - unless you're 14, living at home, and don't have a job. Then yes, it can be a lot of money. If that's the case, stick with the trial, stick with ST2, or... use N++. But please don't complain about paying for upgrades when almost EVERY software vendor in existence charges for major upgrades. By the way, a major upgrade is something like v2.x to v3.x. Minor upgrades are things like v2.1 to v2.2. Typically, minor upgrades are free while major upgrades cost (my terminology may be a bit off, but you get the idea). This is normal business models as far as my experience tells me.
If you think that $70 is a too much money, then think about the other things in life that you spend money on...
$4+ for coffee from Starbucks?
$5+ for a McDonalds meal?
$50+ for an Xbox game?
$50-100+ for a date night (depending on where you are in life)?
$15/mo for a game subscription (World of Warcraft)?
Any one of these things add up very quickly. I have a bad habit of stopping for coffee on my way in to the office every morning. My drink of choice is $4 dollars and some change. That's $20/week, $80/month. If you think spending $80 dollars for coffee is ok, but not $70 for Sublime then maybe you should stick with freeware?