Starting playing some HU, what level to not get raked to death

[jaguar]

After playing a bit with poki i decided to start experiment with limit HU. I want to start low and get used to the play first but how low can you play without the rake taking away any profit you could make against decent players? Assume a 25% rakeback.

is 2/4 possible? 3/6? 5/10?

[timprov]

UB caps headsup rake at .50, so is definitely the place to play. Even 1/2 there is fine.

[Alobar]

stars .02/.04