I also had one or two equipment changes that realy improved my swing and game : 1st before the Adams Tight Lies (Super Concorde clone) came out I couldn't hit a wood straight even if my life depended on it so I used to play blades upto the 1 iron; 2nd I had to wait till the Thrivers came on the market to learn how to hit a driver. But such revolutionary different club designs only come once a decade.
Good pro's that you can connect with are rare to find too. I always suffered from slicing. Moving house a lot, and as such changing golf courses and pro's a lot, but none was able to cure it. Untill my last move some 10 years ago I stumbled onto the club pro who changed my slice into a slight draw in just one 1/2 Hr lesson. I call him "the magician" since then, and he's was the 'true' game changer for me.
Injury is a good reason to change equipment. I changed to lightweight steel after a shoulder injury 2 years ago. I owned 3 series of irons (Ping I3, I-blade and G3), which was a bit to much to change them all. I kept the 20+ year old I3's. It took a year (and my magician) to get used to the lighter weight and get my game and distances back.
Golf lessons are a much better investment then equipment to lower your scores.