Food! If I could make myself eat cheese sandwiches for two meals a day rather than just one, I would have about an extra $3 per day. That doesn't sound like much, but $3 * 365 is almost $1100 per year! I can buy a lot of ammo with that! At $8 per 550 for 22LR, that's 75,000 rounds!
I guess the worst thing competing for my gun/ammo money is gun accessories! $5 for a sling, $6 for CLP, $10 for cleaning patches, $10 hollow-ground screwdriver, $15 for a case, $20 nice cleaning rod, $35 spare pin & spring set, $20 punch set, $? magazines, etc., etc. really adds-up! I keep-up with every single penny I spend, and I've spent more on junk to go with and clean my guns that I've actually spent on guns (a Marlin 22LR rifle & 1/4 of a home-built Oly). Everything gun-related seems to be expensive!