whens it time to replace wedges?

Just been cleaning my clubs and my wedges are starting to look battered. There mizuno mp t ones that i got over 2 years ago, maybe 3 years some the 60 has lots of dings in, and i have noticed i not been getting as much nip with them. 

I try to play at least once a week though alot of the time its 3 times a week. Do you think its time for a change?

so how oftern do you change yours?

And whats opinions on sets is it worth getting all the same make or is mix and matching ok?

Wayne is spot on with the grooves sharpening.

The pro at my club has had is snake eyes 52* for years and years and there is a circle around the sweet spot but he will never part with it.

My wedge is a 53* Cleveland had it maybe 3 year and its the 1st thing I look for 80 yards and in.

Mizuno wedges are very good and I can't help thinking short game lessons and a groove clean would be the way forward.

Remember Keith Flook and his flop shot over a bunker..? That was his donnay 64* wedge which cost a £1.

A wedge is life not just for summer..