Some numbers thanks to BJRM...
Assuming you are perfectly playing 6 deck H17 DAS games with a typical cut and are wonging the $10 tables (flatbetting at $10/hd while the shoe is positive)...
Your expectation is a $11.60/hr win. However, as others have alluded to, you can expect that you will NOT just sit there and win at $11 an hour.
1. In the first four hours you have over a 25% chance of getting your $400 wiped out. 67% of the time you will range between a $345 loss and a $438 win.
2. In the first 40 hours you have a 65% chance of getting your $400 wiped out.
3. If after losing $400, you will give up the game of blackjack forever (which is what you mean by saying you have a $400 bankroll) then you have a 78% chance of someday swearing off the casinos forever.
This is why people are telling you that a $400 bankroll is ridiculous (unless you are playing silver). Now, a $400 TRIP bankroll is different (meaning you are willing to go get more if you need to). Typical RORs for lifetime bankrolls are in the 1% range. (I think bigplayer has said he is at about 0.1% or so.)
As to the idea of putting your entire stake on one hand - this is a terrible idea the way it was written. Blackjack is a horrendous game if you cannot split, double, or buy insurance which is where you are at if you slide your entire bankroll into the circle. This is the same reason why you should never use a typical matchplay on blackjack if you don't have to. Even roulette is a better choice for matchplays.
I will say that going for broke, changing some of the details, isn't a bad idea. You are NOT going to raise any kind of decent bankroll with your method. Even if you do happen to be one of the five theoretical people who survives this at the beginning you aren't going to get any comps being a true $10 backcounter. The expenses (even if you are close to a casino and don't have to worry about rooms and/or long travel, wear and tear on your car-) will overwhelm your $10/hr advantage. But I get the feeling you are a very recreational player who is just looking to go have a good time and feel like he's different from the rest of the goons in the place.
I say - go nuts. Just realize what you are doing. Your $400 is almost certainly going to be wiped out one way or another. Of course, go to a bar 10 times and this is also true. You'll also find that backcounting is an especially lonely way to play. I don't much enjoy it myself. You need to be more educated if you plan to get serious - and this is the right place to start.
Lek Tol
Anubis