How High Heads Up?

I play a lot of heads up games. In order to be a winning player in Heads up, you have to be able win about 66% of your games. 50% will not do. Suppose you played 10 $5 +.25 games. You win five, you lose five. Your rate would be -$2.50 due to the rake. 66% is a good win rate. How high should you play. Wherever you feel you can win 66% of the time. For me it's $5 games. Suppose you can get 4 games in 1 hour and you are successful enough to win 3 of the 4. You win $30 and paid $21 in entry fees(Includes the Juice). That's a win rate of $9 an hour. If you played 30 and won 20, you win $200 and paid entry fees of $157.50. Profit $42.50. Find your game and where you can win 2 of 3. That's the best way to profit from Heads Up. As humor this is what you are playing for when you go one on one.

$1 = A bottle of Coke
$5 = Big Value Meal at Burger King.
$10 = A nice Toolbox for Father's Day.
$20 = A brand new release DVD
$30 = A full tank of gas(Maybe!!)
$50 = A copy of Madden 07'
$100 = A new lawnmower
$200 = 200 Bottles of Coke!!
$500 = This months rent
$1000 = Entry into an event at WSOP
$5000 = A decent used car.