Pi mag or alternatives?

Hi,
I am considering purchasing the extraordinarily expensive Pi Mag water filter but am not sure if it's as fantastic as it claims to be or is just a very clever pyramid marketing scheme. I desperately want to remove sodium flouride from my water alongside the usual heavy metals etc. I am less concerned about the added mineals/magnetised water/alkalisation etc but would like to know if they pose any harm ie/some have said alkalisation can be damaging for type As (me) or that only if it is heavily alkalised. The Pi Mag says it only mildly alkalises.

I do not want distilled or reverse osmosis water but would like an opinion on this or something similar?

thanks a bunch.