hmm well then
So the XT has a speed of 325/600 core/mem clock speeds.
GT has 350/500 (from http://www.techpowerup.com/gpudb/
i found the XT (128mb) on newegg http://www.newegg.com/Product/Produc...82E16814130257
i could only find a 256mb version of the GT on newegg and that was $253 http://www.newegg.com/Product/Produc...82E16814121192
The spec sheet doesnt say how many pixel pipelines the XT had but a reviewer said 8
While the GT has pixel 16 pipelines.
So the 6800 xt 128mb sure is cheaper, though im sure the 6800 gt is better in terms of performance because of the pixel pipelines and 256mb.
So to answer your question: 6800 GT