Actually the 5700LE is no better than the 5200, I suggest the Ati 9550 or the 9600Non pro both of which are available for about 5K.
Lets see, both the Fx5200 and Fx5700LE have the same core clockspeeds and memory speeds, both have the same number of pixel and texture pipelines, though mind you the FX5200 come in the 64bit & 128bit ( memory bus) variants, so make sure which one you are buying , obviously 128bit > 64bit.
So basically they are both the same, but for a few differences like some newer technology in the 5700LE like Ultrashadow and Intellisample, something you would not care much about, also it uses the 0.13 micron manufacturing process against the 0.15 micron of the 5200. In realworld gaming both would give similar performances, the 5700LE could be a bit better. The 5600 would fall somewhere in between these two.
BUT as far as dx9.0 performance goes both suck, the ATi 9550/9600np are better. If you want to go in only for a Geforce Card then I suggest you skip the FX series totally. Go for the new 6 series, but then your budget would bust through the roof.
My suggestion go for the 9600np.
Best of Luck!.
By the way Happy New Year to all folks here.