I looked this one up on Ebay.
Refurbished ones can be had from $40 to $160 but saw one where it said the black back scratches easily.
If you wanted one brand new in the box just to tinker with it, it will cost you hundreds of dollars.
I saw one listing for $3,000 which is ridiculous.
Apple stopped supporting this phone in 2012 but the one in this video can do videos, play games and still make phone calls !