How easy is it to sell a relatively new phone?
 

I've got a red colored GSM Galaxy S3 that I bought in Kuwait (it was imported from Europe I think). It's in perfect condition without so much as the tiniest scratch on the screen, but I've been thinking about upgrading to the new Google Play edition SGS4. My S3 has Cyanogenmod 10.1 on it.

If I upgrade, I want to be sure I can use the S3 to recoup a bit of my costs. How easy would it be to sell? I live in Chicago, so there's no shortage of *potential* buyers.

As I see it, the color is a huge plus because it's extremely uncommon in the United States. As for the custom rom installation, I can see that being either a big plus or a big negative, depending on who is interested.

I'd like to get at a minimum $300 for it, but I'd be more happy with $400-450. Do you think either of these prices would be reasonable to expect in a week or two of Craigslist ads?

And beyond that, is a factory reset and removal of the external SD enough to ensure that all my personal data on the phone is as irretrievable as possible? The possibility of my contact list or documents on the phone being recoverable by a buyer worries me a bit.

You can try these these websites as they buy smartphones.

amazon.com by opening a free Seller account
http://www.usell.com/
http://www.gazelle.com/
ebay.com

If you remove the external card then you're secure right there. However, not sure about the internal storage. Most people do a factory reset and hope that's enough.