Willing to do a trade: Body and more- for a lens

[AMOMENT]

If anyone wants to work out a swap, I'm willing to trade my perfectly kept Nikon D3100 + 18-55mm VR kit lens +rechargable battery+pristine camera bag that fits everything+all cables necessary as well as the manual, for a Sigma lens...anywhere from 17-70mm f/2.8 Macro, or 24-70mm f/2.8, an 18-50mm f/2.8 Macro.