I have found FedEx to be a lot cheaper than UPS. I only use FedEx due to the many, many problems I have had with UPS.
To get the cheapest rates from FedEx, open an acct with them. It is free and simple to do. Only downfall is that you have to register a credit card to the acct so they can automatically bill you, but I have heard you can request to have bills invoiced to you once you are established shipper. You can open the acct online at fedex.com That gets you registered shipper discount. Then, when you ship, do it all online. Prepare the shipment and print your label at home. I believe that saves you 10%, but not sure. Last word of advice, take the package to FedEx. If they pick it up, it will cost you $4 more.