[holdem2000]

I agree that this seems -EV for OP, but how -EV is it? While I only get up to 5 buyins at 200nl about once a week, my sessions are only about 2 hours and I'm playing to maximize EV rather than stack size. Obviously high variance plays are good for you until your stack reaches a certain size. If the bet is large enough you could take as many tables as you're able to play and keep pushing random hands hoping to only be a 2:1 dog most of the time and eventually getting up to about 4-5 buyins on a bunch of tables pretty trivially (after losing, say, $10K).

Also if you're down to about 30 minutes left and have a $1600 stack on one table you can start pushing tons of crap and if you're only a 2:1 dog for stacks a couple times you can still win the bet 1/9th of the time only giving up about a $100 EV at the table.

Edit: If you're not making ridiculous plays like I mention above you're probably better off at nl400 if you're a significantly winning player at both stakes since the extra aggression at nl400 will lead to higher variance.