Batteries that were bought "one or two years ago" aren't new.
Probably, one or more of the "new" batteries are bad. Buy a new set,
and try them.
Much less expensive than buying a new camera.

 Any camera that old that uses AA batteries probably had poor
battery life right from the beginning.  It should be better than 4
to 5 shots thought.  Do you recall what it was (20, 40, 60, etc.).
The way cameras are used can greatly shorten the number of shots you
can get from your batteries.  Some of these include not enabling a
power-off timeout, keeping the LCD display turned on, using a high
percentage of flash shots, and enabling Auto-Focus Mode if your
camera has that feature.  Your battery charger may also be
malfunctioning.  If you don't mind wasting a few AA alkalines, try
taking as many shots as you can get from them without using the
camera's flash.  However many shots you get, figure that NiMH
batteries should provide 2 to 3 times more shots than that if
they've been properly charged.  This should let you know if your
camera is working well or not.

 Just to let you know in case you aren't aware, some of the P&S
cameras manufactured in the last year or two can get up to 500 shots
from AA NiMH batteries with the LCD turned on with many of the shots
using the flash, and 1,500 shots per charge if the LCD is turned off
and the flash isn't used.  If there's nothing wrong with your Epson
PC800 it may continue providing decent pictures for a long time.
But cameras have improved in the last 6 years, and some of the
current models not only perform *much* better (shorter shutter
delays, etc.) but also produce better pictures.