I’ve dealt with this problem also, optiplex 270 sff is notorious for this problem, trying to buy even a 64mb half size agp or pci vidcard costs over $110 to fix, it usually is cheaper(if man hours isn’t included) to buy a new cheap case move the entirity of components over, and buy and install a new standard size 128mb vidcard.
Well those customers are contract, so they pay the same labor rate each month. As long as the PCs are under warranty they refuse to pay for new hardware. Of course when they do its another Dell Optiplex sff(rolls eyes).