Hair Straighteners Advice?

My girlfriend has hinted on numerous occasions over the last couple of months
that her current hair straighteners aren't any good. Apparently GHD
straighteners are far superior to any other product and last longer. My own
hairdresser supports this argument (i was given a lecture about their platinum
plates, how many ceramic plates break,...).
Since it's almost Christmas, I would like to get her new straighteners.
However, they cost at least £90. Surely there's a cheaper copy? My budget is
only £40–£50 (although I guess that she might want to contribute herself?).
1. Are GHD really the best – I'm very suspicious!!
2. Can I buy the same quality for less pennies??
Thanks in advance for any advice!
Niall