$2 per wh seems very high. There was something on green car reports for NCA which puts the assembled price at around $400 assembled with the circuit boards included.
Did you consider common form factor batteries?
I was looking for retail high discharge (>= 25C) batteries. Any link or advice (not an engineer here, I will try to ask some friends to help with the tough technical part) is appreciated - here is what I found
Green Series Life 10,000 6-cell 19.8v Battery Pack, GS LiFe 10000mah Packs, Life-10000-198-Pack
and for the motor
Electric Motorsport EV Parts
There were LiPo up to 120C continuous but much more fragile (charging) and much shorter life (and a bit more expensive). I expect the price to come down somewhat by the time I offer myself this treat (1-2 years) of trying to build a small EV than can do 0-60 mph in less than 3s and then wear out uncountable sets of tires - heck, by that time Model S AWD Sport may be available so I will have a real monster and small devil to play with.
PS: I feel we are getting OT here ...