I'm from South Africa. I'm looking for an Apple iPhone 16GB 3G (In RSA, North America, Europe or India). I don't have a huge budget, max $500. Anyone can help, new or used. Thanks.

This site is selling them for $499:
http://unlockedfones.com/catalog/product_info.php?language=en&currency=USD&products _id=33
or you check this link out and view more online stores:
http://www.google.com/products/catalog?q=iphone+3g+16gb+unlocked&oe=utf-8&cid=6707006704414793956#ps-sellers

Yeah ebay is your best bet try this one right here:
http://cgi.ebay.com/Apple-iPhone-3G-16Gb-BLACK-AT-T-Brand-New-UNLOCKED_W0QQitemZ320307466955QQcmdZViewItem?hash= item320307466955&_trkparms=39%3A1|66%3A2|65%3A15|2 40%3A1318&_trksid=p3286.c0.m14

there are plenty more there for you to look through.