Mathews SQ2 purchased in 2001, still going strong.

I'm having a hard time justifying a new bow purchase considering my SQ2 still does everything I ask of it.
That and new bow prices are crazy high.

I did recently purchase a new cam, but the total after set up was still a fraction of a new bow price.

So how often do you folks upgrade your stick & string?

What would make you upgrade?
Me, it would probably take a catastrophic failure for me to upgrade.