How much should I private sell a iPhone 4 8GB White in good condition?

How much should I private sell a iPhone 4 8GB White in good condition?

Added (1). I have a White iPhone 4 8GB which is in perfect condition other than a few very minor scratches on the screen. Everything else works perfectly (buttons, antennae, touch screen, etc.). I'm trying to price the phone to sell to a friend, but all the eBay and Craigslist prices are for broken or messed up phones. How much should I sell a phone in this condition for today?

150-175 euro, be fast because after iphone 6 is coming out, the prices will drop harder.

Personally, I would consider it for $100-$120. When the new iPhone 6 is launched in September 2014, the iPhone 4 will become obsolete so there will be lesser demand for it. The new iOS 8 won't also run on the iPhone 4 so it will be just as good as a thing of the past. If you want to sell it, now is the right time because you might find it harder to sell it for more than $100 when the new iPhone 6 is released in the market.

With only 8 gb, I doubt it is worth more than $100 or 75 euros. Check completed auctions on eBay, under advanced searches.