Would you buy an (Android) cell phone off of ebay, that was "mfg refurb"? What are the risks? (non-China-seller)

[VirtualLarry]

What are the odds that the person selling them, has placed some sort of Android spying malware, or otherwise, re-flashed the ROM on you? Especially if they are sold as "unlocked"? Is there a way to tell, or to "vet" the phone? I have enough paranoia about stock Samsung phones being hacked OTA, all of my apps running in the background, phone running slow, etc.