Advice for upgrading d70 with Tamron lens

Don't be afraid of used gear. Buy EX or EX+ or LN stuff from keh.com and you'll be fine.

Bodies:

Consider the D80, $254 EX+

http://www.keh.com/camera/Nikon-Digital-Camera-Bodies/1/sku-DN029990949930?r=FE

Or perhaps a D200, $325 EX+

http://www.keh.com/camera/Nikon-Digital-Camera-Bodies/1/sku-DN029990883770?r=FE

For glass:

18-70 f/3.5~4.5 AF-S DX Nikkor $139 EX+

http://www.keh.com/camera/Nikon-Digital-Zoom-Lenses/1/sku-DN079990701840?r=FE

75-300 Nikkor $109 EX+

http://www.keh.com/camera/Nikon-Digital-Zoom-Lenses/1/sku-DN079990992000?r=FE

70-210 Nikkor $89 EX

http://www.keh.com/camera/Nikon-Autofocus-Zoom-Lenses/1/sku-NA07000021000N?r=FE

So, suppose you got the D80, the 18-70 and the 70-210 used. The total would be $482 for a body and two lenses.