If they could somehow sell the TVR T350C or Segaris in the US for $80,000 I don't think they could get enough here quick enough to meet the demand. Sure, Americans love their Vettes and Vipers (as a matter of fact I almost prefer them), but TVR is third behind the other two unquestionably.
A quick comparison of prices c/o Dream Machines Kent and Sussex UK, currency exchanges by Oanda.com:
2006 TVR Segaris: $96,138.70 USD
2006 TVR Tuscan S: $93,519.90 USD
2006 TVR Tamora: $ 74,873.90 USD
2006 TVR T350t: $ 65,963.20 USD
Those prices aren't horrible to say the least, esp. with the performance/price comparison you are getting. The Segaris is the only TVR that can match the Z06 in terms of performance, and even at $96K USD it is still a fantastic deal when compared to similarly performing Porsches and Ferraris. My knowlege of the Tuscan is pretty much limited to videogames, but I still do not think $93K USD is that bad either. Hell, the T350t at $65K is probably a good deal compared to a Vette Z51 and a Viper SRT-10...