D700 vs D300. An ultimate choice to upgrade after D50

With new Canon EOS50D and the Ultimate 5D mark II in the market, a lot of people like to compare them with Nikon D300 and D700 respectively. Since I am a Nikon user, I do my best noy\t to switch system since its gonna cost me a bomb. Anyway I am looking forward to change a new camera though. My Nikon D50 is dying soon. Its time for me to retire it cos since 2005, I have taken more than 40,000 clicks. Although its not much compare to a professional usage, I got to say my camera starts to make that strange noise ever time I took a shot. Now the plan is December 2009. I got a choice of D300 or D700 (due to my range of lens). I am using those old lens and some of it cant be use with the lower range probably including the D90 and D5000. Anyway my budget is about 3k. So..... going thru the specs review in nikon.com.sg I got to say D700 is very tempting. But the only thing is that it uses FX format (full-frame). I can't afford its compatible lenses. Next I look at the D300 which are more popular ones. Like I say, I look at the specs and sees no diff among the two. Accept for the sensors. You can look at the specs here http://nikon.com.sg/compareproductitems.php?p=1257-63bae4a413,1187-59711d5d33

Anyway, D300 is much more cheaper and an ideal way to upgrade from my D50. Besides after that I can tell the missus to upgrade some more.hehehe