When is the time to change clubs?

Thanks for all the input on the blades thread. But on a more budget note, when do you know its time for a new set of clubs? i mean id like a new set but do i need a new set?
When do you know that your old ones are no good or holding you back?

Why do you think you need new clubs Mat?

To my mind you buy new clubs when you have the money and the wife does not know.

Just make sure she does not look at the golf forums and you are laughing.

Basically Mat you don't need new clubs for your game do you?

If you play quite well with the ones you've got why change them, if it aint broke don't  try to fix it. 

Matt I can agree with all the points above but the main one for me is what you want to achieve?

I recently changed from a set of cavity backs that I had owned for 4-5 years hit well but lacked any real feel to my shots. I have now been using a forged/blade style iron for 3 months and the feel can not be compared however off centre hits are bad and I now hit more fat shots due to the thinner sole and less bounce