I updated my surplus Beretta 92FS with a new spring kit and SS guide rod. They're not expensive and ordered from Brownells, got them in my hands within 5 working days.
I got 2 sets of springs and 2 different SS guide rods for about $90 US. Picked the spring weight I wanted and the SS rod I preferred and sold the rest on the EE, including the used parts. After all was said and done, what I kept didn't cost me much at all. My 92FS felt like a brand new gun afterwards.
I was interested in the D-Spring to lighten the trigger weight, but the SA trigger is quite good on mine, so I didn't bother.