My DS was past the point of fixing by anybody in my area, and the replacement parts plus service fees anywhere would have outweighed the $50 I paid. Parts for the Phat are also insanely hard to find from my experience, as nobody sells them....anywhere. You basically have to salvage usable parts from old, broken Phats.
Also, I got it knocked down from $75 and having to pay for my own shipping, so I figure I got an okay deal overall. The two screens were the core problem with mine, with possibly more than just the actual screen being messed up with the touchscreen. That, and my battery was basically shot. No more than two hours in DS mode with no sound on what so ever.
If it's a lite, you can find all the possible parts to fix it yourself for relatively cheap.