My SP1 has been running fine for quite a while now on a Duracell. You can get a 4 pack for about $8 here (@ Canadian Tire, for you CDN viewers). I bought a pack, dropped in a fresh one and played for about 9 hours. It missed a few shots (I waited a second and it would fire, but when shooting quick it would miss). Not wanting to lose due to a dead battery I swapped it out again, although it worked fine in my Revvy. Anyway a fresh battery and it's been good for about 12 hours of game time (over 3 Sundays, 4 hrs each). I shot it a bit yesterday out back just practicing... it's fine still.
CO2 is pretty good too. I'm getting about 1200 shots to a 20oz CO2. Given that CO2 tanks are dirt cheap, I can take 2 with me to the outlaw field and play an entire case. Then bum some more