It's pretty rare for people to talk about how many copies they sell. I suspect that since tabletop games often sell fairly small numbers of copies, people might feel embarrassed. 

I've been around long enough to have had a lot of results, so lets share a couple:

FiveCore skirmish (3rd edition) has sold 1234 copies with another 1164 when we were in the bundle of holding. 

Thats pretty good in the indie sphere. Platinum seller on Wargame Vault, which less than 2% of titles achieve. 

Ballad of the longbow has sold 88 copies. Thats about what I expected for that game. 

And for comparison, Five Parsecs has sold over 10k copies in the current edition and sold about 3300 copies in the indie 2nd edition. 

So what's the upper limit in the "cheap looks and indie production" sphere? Well, I suppose 1k to 3k copies is about it for me, for now. Hopefully we will blow past that in the future. 

What is typical? That is difficult to say. Around 65% of products on Wargame Vault do not sell enough to reach Copper status (which I believe is 50 copies or so). RPGs do a bit better with 60% failing to hit that mark. 

In other words, the majority of items don't really sell anything significant. Of course this may be skewed by the fact that some items are not marketed to be sellers, but made available because the creator wanted to do so or they are so incredibly niche that they just don't really stand a commercial chance. 

What about itch.io?

I left Itch out because I don't use it currently. I have seen some writers say they get a decent amount of revenue from it and others say that it really doesn't account for much. I suspect it may depend on individual circumstances.