Well it also depends on the setup they have. If they don't have an SLI compatible mobo then they would also have to replace that, also possibly causing you to have to rebuy RAM (if the old mobo was DDR2 and the new one was DDR3, for example). In addition an SLI set-up tends to be very power hungry which also might require a PSU upgrade. The current upgrade is probably just a replacement video card and nothing really needs to be changed (maybe new video card drivers), otherwise it's a very simple upgrade. There are many factors that may go into this decision. ;-p
Should be a sweet set-up, I wonder how it'll go. :)
starcraft: "I and every PS3 fanboy alive are waiting for Versus more than FFXIII.
Me since the games were revealed, the fanboys since E3." 
Skeeuk: "playstation 3 is the ultimate in gaming acceleration"
