what is your cpu, ram etc... click on the dropdown menus on the link i sent u and select your parts. then, in the video card list, try to find one that doesnt put you over 250w.
first wth u CAN REPEAT WITH ME U CAN upgrade ure power supply dell just wants u to buy a new pc maybe they offered u a coupon or something u could put a 450 watt psu without a problm so buying an agp card wont be that much of a problem if u buy a new psu
last time i talked to him, he said he was going to get the x800gto agp card and a 450w psu. it came to a total around 200 with shipping and tax.