I have to add my expertise here
First off check out for local feed stores. I raise and show rabbits so I know where to get the good deals. Look for an agway or something of that nature. Ask for a bale of shavings....forty pound bag 3 dollars, then get a fifty pound bag of any rabbit feed for about 8 dollars. I find the mice will soil there crocks so check out
www.damars.com for cheaper housing supplies. THey can custom build just about any caging system you like. Or get a huge rubbermaid roughneck tote from walmart. Hope this helps....feed stores are always cheaper!! And with the shavings they aren't on the shelf (the ones that are are expensive) as for them by bales at the counter and if you can't find a feed store look at horse tack shops!