That's what my group does, and no doubt, it's a little odd. And pretty much everybody who plays at that table is prepared to re-buy up to $100 or more. So why do we all start at $20? No idea. It's just what we do.
The short stacks seem to result in early all-ins, which results in lots of rebuys, and as the night moves on, the rebuys becom 30 or 40 or 50, so the money gets out there.
So yeah, we start low, but it works for us. I would never sit down at a casino with 40 big blinds, no way, never. But that's how this particular home game plays.
My crew was like that for a long time. I finally started buying in for $40 one night and some followed suit and some didn't. A few of the guys would do weird numbers like $27 or $31 just to be different. We have one guy who never rebuys after he busts and then a guys like me willing to go up to $100 or a little more. It's a buzz kill when no rebuy guy busts and leaves early and all of a sudden we are short handed for the rest of the night.