[G4] G5 or newer G4?

[the Claytons]

I've decided it's time to buy a new used Mac. My Quicksilver 733 G4  
is getting long in the tooth and I've gotten all these years from the  
original hard drive, but I worry.

Logic says that a G5 is the way to go, still, I'm intrigued with the  
idea of a "late model" G4 (perhaps a MDD 1.25) that I can max out at  
perhaps half the price. I need to stay with Tiger.

I'm recently retired so I really don't need the latest and greatest  
and fastest. But I do want to get many years service from it.

Any ideas, arguments, suggestions?

Ray