Bryan, I find that whenever we make decisions, we get the best results when we know the facts. Let me offer you a few facts that might help you evaluate your options.
1. The median selling price when using an agent is 16% higher than when homes are sold directly by an owner. (According to the National Association of Realtors, Home Buyer and Seller Survey, 2006) Even if you paid a 7% commission, that is still 9% more in your pocket.
2. If you sell on your own, you must pay for all the advertising and marketing materials. (This expense is normally paid for by your agent or broker, should you use one.)
3. Buyers buying direct from an owner typically expect to pay (and intend to pay) less. (see item 1, above)
4. Selling on your own usually takes longer than with an agent. This results in additional taxes, interest, utility bills, insurance, and potentiall additional travel expenses back and forth if you move before the marketing of your home is complete.
5. Without an Realtor, you may have to engage an attorney to prepare or review contracts for you. This is likely to cost more than a Realtor's services would have, and attorney's fees most often will be billed to you even if that sale does not go through.
When buying a home, and using a Realtor as your "Buyers Agent", you are free to negotiate your contract with them, just as when you hire them to market your property. It is possible to structure your contract with them so that you pay nothing out of your own pocket. A Realtor, with their available resources and local market expertise, will also be able to save you money in the negotiation process on the purchase of your new home.
So, I think you can see that your original question had a flawed premise. (Which I think you even hinted at when you said, "but again, I wonder if that's even realistic." In fact, using a Realtor on the Selling side typically nets you more money, and using a Realtor on the buying side costs you nothing, and potentially saves you money on your purchase price.
For an article about the "Value" of working with a Realtor, please see http://activerain.com/blogsview/98782/A-REALTOR-s-Worth
As always, I wish you luck in selling your home. If you need any other questions answered, please don't hesitate to contact me.