You can keep the 28-105 and get equal quality. But now you will have like a 42-150mm zoom, so you will probably buy a 20/2,8 later on, cuz you will miss the wide-angle.
If you trade the 28-105 and get the new 18-70, you will instead get like a 29-105mm lens, and maybe buy a tele zoom later on.
Personally, I think the new 18-70 is a more flexible alternative to start with, cuz it will cover most photographic needs. Later on you could get a lens like the 70-300 and cover like 105-450mm. Then when you can afford it, get the 50/1,8 which is a great low light lens as well as a nice portrait lens, like 75/1,8.
I have a D70, and I am very pleased with the 18-70. My second most used lens is 50/1,8.
Good luck!
Hans
If you trade the 28-105 and get the new 18-70, you will instead get like a 29-105mm lens, and maybe buy a tele zoom later on.
Personally, I think the new 18-70 is a more flexible alternative to start with, cuz it will cover most photographic needs. Later on you could get a lens like the 70-300 and cover like 105-450mm. Then when you can afford it, get the 50/1,8 which is a great low light lens as well as a nice portrait lens, like 75/1,8.
I have a D70, and I am very pleased with the 18-70. My second most used lens is 50/1,8.
Good luck!
Hans