The current price of a new D7000 body is running ~$897. Most of the online deals with trusted sellers offer it with the kit 18-105 for another $100 or ~$997.
Those same sellers offer a new 18-105mm for ~$250. I could see a quick eBay sale of $200 for a NIB 18-105 for $200, a $100 profit, but.....
D5000 bodies alone don't show much action in the eBay sold section above ~$200. D5000 with the 18-55 bring ~$300-400 (all dependent on condition/shutter count).
In summary, I'd sell the D5000 with the 18-55, buy the D7000 kit w/18-105, sell the 18-105 and since you have the 55-300 buy a 35 f/1.8g for ~$200. All that should leave you with a few bucks start towards a fast zoom to complement the 55-300. You'll like the 35.
Those same sellers offer a new 18-105mm for ~$250. I could see a quick eBay sale of $200 for a NIB 18-105 for $200, a $100 profit, but.....
D5000 bodies alone don't show much action in the eBay sold section above ~$200. D5000 with the 18-55 bring ~$300-400 (all dependent on condition/shutter count).
In summary, I'd sell the D5000 with the 18-55, buy the D7000 kit w/18-105, sell the 18-105 and since you have the 55-300 buy a 35 f/1.8g for ~$200. All that should leave you with a few bucks start towards a fast zoom to complement the 55-300. You'll like the 35.