I think I have seen the price drop down to like $1130 or something like that.
Phantom Grip makes an affordable alternative. It consists of two blocks with stiff springs that ride on the carrier shaft of the spider gears. Although not a true LSD, it would be enough for any street brawler. Price is just under $300.
I actually have a set that I have yet to install. Got my TRD LSD shortly after and just been too lazy (busy) to install it.
Phantom Grip - Scion tC 2-way LSD