The best deal I have found is to get the cash credit from Radisson, then using miles get a revenue ticket and up grade using miles to first or business. On UA, for 25k you can get a 1 class up grade on a m or better class ticket in coach. They uses to allow double -ups but that has gone.

If you work for or own a company that has an air cargo contract with an airline.... you can get comp. up grades, outside the frequent flyer program, from the Cargo sales division. If you know a airline staffer..... you can get buddy-passes too..

I used to get cargo sales certificated all the time. They trump a frequent flyer certificate as it is the airline rewarding a contract agreement.