ORIGINAL: oxide80
I bought my EVX-2 and both Titan 550's as a package used on Ebay for $50 included shipping about a year ago. Not a bad place to look.
+1 For $50 you can get new ESCs (like tamiya's teu-103bk) that will handle dual motors fine, but they wont handle motors that are a lot more powerful than 27 turn ones. ESCs like the Traxxas evx2 and the HPI GT will handle higher power motors, but they cost more. A used evx2 or GT would probably be your best bet.