You do not mention your person financial circumstances. If you have an awful lot of money stashed away then by all means have a go. If not then you would be well advised to invest your money into your pension fund rather throw it at Bristow.
You would also be well advised to have a look at the gloabl helicopter market which is closely tied to the oil market and has not been in such dire circmstances for quite some time. There must be thousands of well qualified helicopter pilots unemployed at the moment and with little prospect of any change in the near future. Also have a look at the £/$ exchange rate if you are considering training in USA.
Well done for seeking advice before committing yourself.