the slower cheeper speed, they want YOU to upgrade so they can charge you more. If the 265k were upgraded to 512k for the lower price, then fewer people would bother to upgrade. I was happy with 512k and would be happy to go back to that for the lower cost.
256k is used as a step up from dial up as the price structure shows, Only a 99p difference click here so i cant see them increasing the speed it is designed purley to entice people away from dial up who wouldn't nescacerily buy into broadband 512k for whatever reason. Then if they like it invest in higher speeds. (well thats my take on it anyway)