Hi George , so someone advised you to spend over $3000 on a D700 and prime lenses , that you don't even need or know how to use , when you stated that your budget was $400 ..... "to save you money" ! ?
Perhaps that's why they say " How do you make a small fortune in photography ? ..... start with a large fortune !"
Did this guy have one eye bigger than the other , head tilted to the side , drool out one side of his mouth and a twitching eye-lid ? Perhaps a "Nikon rep" card on his jacket ? Just kidding , he probably meant well but he made some huge assumptions that you would
1.) stay with your hobby for a long time ,
2.) actually want to go full frame ,
3.) be prepared to sell one of your kidneys to finance the purchase or go into debt , and
4.) be willing to lug around a heavy camera with two lenses that he likes rather than perhaps what may be right for your needs .
[ To be honest I wouldn't swap my D90 and 18-200VR lens for a D700 with any prime lens - that's a personal preference though ]
My advice - for $400 you could get a good used Nikon D50 and 18-55mm lens plus perhaps a used SB24 flash that will give you good image quality and superior flash synch speeds to a D700 and the equivalent of 6X the flash power of a D700 in high-fp mode using what I call realsynch flash . Until you understand what the heck I am talking about it is pointless for you to get a D700 unless by some unlikely chance you will start making money from low-light photography in a few weeks.
The D50 is 6 megapixels which is more than enough for most of us -[ they printed a 3 storey high image from 12 meg ], has decent high iso performance and the 18-55 lens will provide you with a reasonable wide angle for landscapes along with a usable 55 mm at the long end .
Think about it , if you buy that D700 brand new it will be worth less than half what you paid for it after three years . The used D50 will still get you at least half what you paid for it in that time and you will only have lost $200 for its use compared to $3200 plus the interest you would have to pay on the loan along with insurance costs of the D700 kit [ perhaps $3500 total ?] .
Invest in last year's technology , don't waste money on today's latest gadgets unless you are making a living from your hobby . When these companies bring out a new sensor it goes into their latest pro camera . After they resolve the initial teething problems with the camera they release a semi pro model with an improved sensor . Then they bring out the advanced-amateur version with further refinements . lastly they bring out a beginners camera with a perfected sensor while they release a sensor with more [unnecessary] megapixels in their latest pro body .... and repeat the process .
You end up with a camera like the D40 with a 6 meg sensor and image quality that puts the first professional 6 meg cameras to shame ..... while everyone clambers for the latest 10 meg sensor with all it's new teething problems - and someone wants you to buy a D700 as a beginner ?
The sad fact is that there are still professional photographers out there that seem to believe the latest gear takes better pictures while the reality is that you can do a lot with an entry level camera and nobody will know what camera the image was taken with anyway .
So my advice is to get the used D50 kit , learn to use it and as you advance you will know where you want to go from there - whether you need to spend more money on newer gear or still need to learn the basics .
Maybe next year you can buy a good used D90 from someone who upgrades because their D90 "doesn't take good pictures" , if your finances allow for it . If the D50 is still serving you well invest in lenses rather than another body , they maintain their value .
Take advantage of the people that seem to think they need a D700 to start with and then sell it cheap later because they either aren't interested in the hobby any more or realize how hard it is to make money from photography .
Buy the old technology cheap and cut your losses .Who knows , maybe in 5 years time if you are still keen on it the D700 will cost you $400 :) .