IMO,
Pliers are like any tool, if they are looked after and only used to work on copper wires (which means not trying to cut steel wires with them) and you don't cut live cables with them, they should in theory, last a very long time, provided you don't abuse them, by using them as a hammer.
My Klein's cost me NZ$65 when I bought them, I've been very happy with the way they have performed.
Spending a lot of money on a pair of pliers can be a dangerous move, you need to keep a good eye on your purchase.
