cheapest retail seems to be from www.trdracing.com
for $475. there's always the occasional ebay item which i've seen sold as low as $200. it'll be a while until i get mine since i'm going to concentrate on upgrading my suspension (b&g coilovers, hotchkis rear camber links and front strut bar w/camber plates, TRD
sway bars, hypermotive rear 3 piece stress bar and suspension techniques' bushings) and my transmission (MAYBE a TRD
jdm lightweight flywheel, clutch set and lsd).