So, I have three guinea pigs and a rabbit and I am learning new stuff to feed them and to let them play with and do everyday! I love my guinea pigs and my rabbit, however all the things that they need can be quite expensive (food, toys, things to chew on, hiding places, etc.). I buy my guinea pigs food from the Food Lion, Walmart, or Tractor Supply for $5.00 and buy the rabbit food from Farm Bureau, which is a small store that has horse feed, dog food, and rabbit food plus vegetables and flowers to plant (really good price too! We pay $3.00 for 5 pounds of rabbit feed).
I give my guinea pigs and my rabbit a soda box cut in half to play with, hide in, and chew on (they love!!!) and I also give them toilet paper rolls (or paper towel rolls) to chew on, as well. We buy Pine Shavings from Tractor Supply (it's called TSC Premium Pine Shavings 63.7 L) and use them to fill the guinea pig cages and the rabbit's litter pan (small animal litter pan, they are a lot less messier that way). I also buy Pine Pellets to put in the bunny litter pan called Cozy N Fresh and we got it at Tractor Supply for around $6. They are very absorbent, are safe for the animals (even if they eat it), and are eco-friendly (they turn to dust when they need changed).
Now, I know that if you read online they will urge you to stay away from this type of bedding but I have never had a problem with it, it makes the cages smell good, and it is pretty absorbent (my guinea pigs are 1 yr old, and two 8 yr old and they haven't shown any sign of sickness). In fact, they are nice, healthy, and constantly squeaking at everything (lol).
I also use zip-ties to hold the water bottles in place instead of the poorly made drink holders---see tips & tricks up above for more info. The rest of the rabbit cage I put down newspaper all around the litter pan (it takes up a whole corner) and layer it to like 3-layers, then I put some bedding on top (pine pellets then pine shavings).
Also, guinea pigs and rabbits need Timothy Hay to keep their digestive systems working properly--if you run out of it, then you can give them regular grass out of your yard (wash it first) until you get some more. My pets love when I pick them grass out of the yard (especially the really long grass that grows around the fence). Don't forget that they need exercise as well!! I take mine out in the yard and let them run around in their cages (I take out the bottom pans and sit something on top) so that they can eat grass and run around to their hearts content (Their cages are really big!!). I also let them run around my room and put them in a play pen out in the yard sometimes.
Another thing is that they love vegetables and fruits-- Google online to find out safe ones. I usually do carrots, green peppers, raisins, seedless grapes, and orange slices (no peel or seeds).
**I just blogged this, in hopes that I could help out some of you out there who either don't know what to do for your guinea pigs/rabbit or are thinking that they are too expensive to have:)