It sounds like you want to use compost to add to a garden section at your parents' home (or your home, to which you return now and then from college). I'll make some additional assumptions in my post. You can try worm composting (aka vermicomposting) at your school/dorm/apartment. It doesn't need to take up too much space and the amount of scraps you need per week would be much less than it is for a 3x3 pile of compost (though admittedly, you can add a small amount to a compost pile at a time, it doesn't need to be large amounts) Take the results of the worm composting back with you to your home. The other thing I can think of is that if you're not home to monitor your garden area, then probably you can reduce the amount of space you are gardening in, and in that case, store-bought compost bags might be a sufficient supply for the time-being. Another idea is that if you aren't getting large amounts of scraps at a time, then using trench composting, you can still amend your soil by using the small amount of scraps you do get. This is ideal for a situation where you may be home on the weekends, and want to use those scraps right away, but for the rest of the week, you are at school (where you do vermicomposting)

Nursuries/garden centers and big box stores (home depot or Lowes) sell it by bulk. Also, look in the Georgia Farmers and Consumers Market Bulletin ads online. See link below. Or go to Lowes and get the 3 cu. ft. bags of pine bark mini-nuggets for $2.98 a bag (sku # 87940). Mix it in with your dirt. It works great! They also sell an excellent Organic Soil Conditioner by Garden Plus (sku # 97675) made of milled pine bark 2 cu. ft. bag for 2.84. It is better than the Nature's Helper because they don't put all of that sand in it. Sand is volume and weight and cheap, but of no value to the soil. But it breaks down more quickly than the mini-nuggets do. The mini-nuggets keep their volume longer and allow air to get to your plant roots. Do a soil test to see if you need to adjust the pH of the soil for the plants you grow. Garden centers/nursuries or the U of GA county extension (1-800-AskUGA1)service will test your samples for less than $10. A good source of free or cheap mulch is from tree removal services. Most of them have to pay to dump their wood chips at a landfill. So if they are local to you they will bring it to you for a few dollars to cover their gasoline expense. I have had some give it to me free, but if it is a hot day I'll have a pack of cold Cokes in the fridge for them. I have them dump the pile at the side of the yard and spread what I could not use in a mound about 2 feet high. It will grow wild mushrooms/toadstools and such fungus type stuff that breaks it down rather quickly. If you turn it so it gets air it speeds things up. Otherwise it takes a couple of years or so to make good black compost. But don't put these wood chips next to your house. Keep them at least a foot away to minimize the risk of termites. Don't dig or turn the dirt within a foot of your house, either. There is a toxic chemical barrier in the dirt to keep the termites away from the house. John Here is a link that might be useful: GA Farmers & Consumers Market Bulletin ads

Around here there's a local company that accepts garden "waste" and sells compost. Most towns now offer the same kind of product; the quality really varies. Alternatively, if manure would work for you, you can search out horse farms (or dairy farms, better yet) where you can often pick the stuff up for free. There have been some restrictions placed on the farms lately, because of public health concerns (misplaced, IMHO), but if you introduce yourself you might be able to score a few yards of well-rotted manure.

One good place for compost and topsoil is soilutions (see link). However, if you just need fill dirt then there is always someone on albuquerque craigslist that is giving it away. Here is a link that might be useful: Soilutions