price has gone down because canon released EOS 450D which equiped with a 12 mega pixel CCD and some more stuff. pricetag is £600+ here, with ultrasonic motor lens and 400D is around £350.
this is the best entry level DSLR in the marcket and 450D is the 4th generation, if the price is too much go for 400D. if this is your first DSLR, u have lot of experiments to do, so 400D and 450D doesnt make much difference in that sence
buy a high speed memory card, like UltraIII or extremeIV, dont go for unbranded crap that they give in bundle deals, memorycard speed comes to play when u use the camara in continuous shooting mood(machine gun mood that allows to take 3.5 frames/second). and make sure you gave enough capacity, because one picture comes to around 2MB in JPEG mood
lenses are expencive, and depend on what u r going to do. if your main interest is wildlife, go for telezoom, portraits, 50mm etc(you may alredy know), its better to buy one lence and practice with it, then buy another lens on experience by mastering first one(nattham passe duka hithenna puluwan). you can buy zigma lenses because they are cheap and not that bad and the pro canon lenses, which are very expencive, are marcked with a red ring. dont forget to consider apiture of the lens when u buy.