That's not an easy question. Basically, you're asking how long is a piece of string. :) You're right that people generally don't tip... except when they do. But they also won't buy unless they're really interested, in which case a $2 price tag won't be an obstacle to most of them. The hard part is getting a lot of people to look at your game at all in the first place, and this is where simply putting it online won't be enough.
Viewing post in How many purchases should I expect to get?
Thank you very much for your insight.
You say putting it online won't be enough, and of course I understand I can't just upload it and expect hundreds of purchases, but what would are some ways to get people looking at it in the first place? What comes to mind immediately is thumbnail, tags and title. Is there anything I'm missing?
Again, thank you very much for the comments.
You're welcome. To answer your question, promote your game! Post a release announcement here. Shout about it on social media. Tell all your friends. And if you can spare a few bucks, even consider a little paid advertising. But most importantly, engage with people so they know you exist in the first place.