Yes I think you will, unless you buy a very modifide one you will be dissapointed. I love my KDX and you would not be dissapointed if you road it. BUT every thing I have done you can do to a 2002-2005 YZ 250 or KX250 and have a much better bike in the long run or buy a KTM and ride. IF I had it to do again with what I have learned I would do one or the other.
Things I have done to my KDX 220
bike cost 2200 with a new motor from FRP racing, that includes a ported, plated cylinder, milled head, carb bored from 33 to 36mm. FMF desert pipe, 10 oz flywheel weight,CR High mini bars,tall seatfoam, fastway foot pegs, KX forks, new springs, pro action revalved and tuned suspension, hydrolic clutch, clark 3.6 gal tank.
all just to keep up with the new bikes and it does very well.
I have about 4-5 grand in it.