the truth is:
the 600cc bikes are not in your price range either. you should up you price range to $5,000. this will pay for the bike, a year of full coverage insurance, riding gear, and most importantly the motorcycle safety course.
the 600cc will cost twice to three times the amount on insurance alone.
EX250 should only cost 1500-2000 used, if they are asking any more than that, they should be able to justify it with visibly modified parts(stainless steel brake lines, Muzzy Exhaust, or intake modifications). if the bike is stock, and they still wont come down, they aren't worth your time, and you should go to another dealer, or a private seller. and when buying a bike, tell the dealer to talk about the "out the door" price, which includes any fees, that may come with the bike and any taxes, if they do it it includes licensing, registration, and most places do that. the "out the door" price is what you will give them to take the bike off their hand. never deal in floor price. only out the door price.
the Kawasaki EX250 Ninjas are great bikes, and really show their origins in the curves. but are easy enough for the beginners, it is not too hard to modify the suspension to get the motoGP racer, it was born to be, out of it.
good luck and I hope this helps.