low limit heads up LIMCASH

[jomatty]

im sure this has been discussed but i couldnt for the life of me find it (take this for what its worth as i can never find anything using search so...)

im wondering what the lowest limit that can be profitable played heads up. i know there are lots of variables that change from opponent to opponent but im just curious what the consensus is as far as long term versus a variety of opponents. i have a pretty good win rate at 3-6 and 5-10 heads up but so much money comes off the table at these stakes relative to whats in play and what is available to be won that i wonder if it is sustainable and if these games are worth playing?

any opinions are appreciated,
matty h