LSD is Limited Slip Differential, my car has a mechanical one, the older models had an electronic system that worked in a similar way but aren't as effective.
Still if you aren't going to be at the ring every other weekend, you probably won't even notice it!
The upgraded stereo features are awesome though, but you can get an aftermarket kit to do that job anyway.
I reckon if you play the long game you could barter quite a bit of money off that asking price.