$3 for a site really isn't that bad, all things considered. It's less than many image downloads on istockphoto.
the more i think about it the more I regret posting this... not to mention for most ppl on this site, they will want the $50-255 dollar license and not the $3 version
I think he has every right to ask a price for it. That also shows he has the intention to maintain it. You can't create the same thing for that price, unless you work for less then $0,25 hour.
Getting something like this working cross browser takes a lot of time. Even for commercial use, this is a bargain.
I haven't seen any other tool tips this good in the open source world, but I'd rather use something good enough open source than use something closed; given history open source will catch up sooner or later
If his stuff is better than the open source stuff, go for it.
You can always move to the open source code later. And think, by then it might have caught up with him, and you'll only have to update your code once, rather than each step as the open source code catches up (assuming it does).
I've taken a look at his other scripts, great stuff, frequent updates. I don't think open source will be catching up any time soon.