WTB Used Road Bike for touring and first tri

I am hoping someone out there might be able to have something to sell me that would be agood fit.

I had my brand new Giant OCR3 (admittedly a beginner road bike) stolen two weeks after purchasing it. And saving money for a similar model or better has been tough. I am 5'7" and am looking for a decent used road/racing bike. I'd love to spend around $500. Not sure if that's enough but would hope there is someone out there that can help.