I have upgraded lenses through the recent years and these lenses are available. The glass is excellent in each lens. All are Nikon mount, full frame. Lenses will be shipped FedEx ground to conus.
Tamron SP 24-70mm f/2.8 Di VC USD Lens for Nikon DSLR
$675
Tamron SP 150-600mm f/5-6.3 Di VC USD Lens for Nikon
http://tamron-usa.com/product/lenses/a011.htmlI have only used this lens about dozen times. Glass is excellent. Purchased Aug 2014 from authorized USA dealer; 6-year USA warranty (not gray market).
$700
Tamron SP 70-300mm f/4-5.6 Di VC USD Telephoto Zoom Lens for Nikon
http://tamron-usa.com/product/lenses/a005.htmlExcellent condition, used very little.
Purchased June 2013 with 6-year USA warranty.
$300
Tamron 28-75mm f/2.8 XR Di LD Aspherical (IF) Autofocus Lens for Nikon
http://tamron-usa.com/product/lenses/a09.htmlExtra lens hood.
Glass is excellent.
Purchased from authorized USA dealer but 6 year warranty has expired, (not gray market).
$250