Alterna shampoo? Joico?

[cashmerecardigans]

Hi
I really need to invest in some good quality shampoo and conditioner. My hair is really dry and flyaway and I've tried no end of different high street shampoos and nothing seems to make a difference.
I used to use Joico kpak years ago so could go back to that, but it's not sulphate or silicon free. I've seen some Alterna shampoo that looks great, called caviar replenishing, but it's very expensive.
Has anyone any experience of using it and us it worth it?
Thanks

[PedantPending]

Yes I have been using Alterna for years. Very good stuff and does what it claims. I currently use bamboo for coloured hair, but have used caviar in the past.
I find a bottle of shampoo lasts me about 3 months with daily usage. Cannot comment on whether it is expensive or not as I live in Europe with a fairly high disposable income.