Having just read your most recent post I would recomend the following:
1. Put Nikon lens on Nikon cameras.
2. Check out the Nikkor 24 2.8 AF. I see this lens all the time at B&H
in New York for around $300. Check out thier web page.
3. Look for a used one. A lens like this in good condition should be
bewteen $175-250. And maybe even less on ebay the auction page.
4. Take a look at the gear you have. Maybe there is something you can
trade or sell to offset the price of buying a wide angle lens.
5. I would stay with the prime. If you invest in the 24-120 you no
longer need the 35-80. However, having said that, you could sell or
trade the 35-80 to get into the 24-120.
Good Luck.
Sam