My biggest expense, by far, is for fresh veggies. I'm sure produce is way more expensive here than where you are. A small head of romaine is about $2.00, and that lasts for two-three days for my two piggies. Red bell pepper is $5.99 a pound, but the girls don't like it. Cilantro is $1.29 for a bunch (the stems would make a circle about a nickle in diameter). You're lucky to have ample free veggies!
A 2-lb bag of Oxbow Cavy Performance pellets costs $7.00 and lasts about three-four weeks. Hay is cheap, I can't remember how much, though.
I use fleece, too, but use Carefresh in their litterbox. Wal-mart sells a version called Critter Care that costs $4.00 for a 10 liter bag that will last about two weeks. $7.00 for a pack of 32 puppy pads (a month's worth).
The biggest expense was setting up their cage in the beginning. $14.00 for a pack of cubes from Costco. I spent at least $50 trying different kinds of bedding/fleeces. Hayracks, water bottles, nail clippers, food dishes, litterboxes, hand-vac (for sucking up poos), shampoo, hidey-houses, brushes and combs all came out to be about another $100.
A sleepy pig (or two) snuggling on your lap while you're reading piggie newsgroups = priceless! (She even has the "sexy leg"!)
The most important thing to remember: Make sure you have an emergency fund for medical care. It breaks my heart when pig-parents post for advice about medical problems and tell us they can't afford to take their babies to the vet. It's a crappy situation to be in, and I hope it it never happens to you. It can range anywhere from $50 for an office visit to hundreds (or more) for surgical procedures, so be prepared. This isn't so bad if you're a grown-up, but some of the younger members of this group encounter resistance from the folks who have to pay the bill, their parents.
--Smoot,
Peanut and Domino's mum