Ebay could mean like 500 different brands from china or wherever. What exactly are you looking at?

Magnaflow or dynopro mufflers are under 100 each when you only need like 2 1/4in sized mufflers.

Just be aware that any aftermarket muffler will sound like a helicopter when it goes down into 4 cylinder mode. The factory mufflers do a better job at muffling that sound. Ideally you'd want to disable the AFM/DoD system before it gives you a problem anyway.