Motorwerks of houston charges $600 to install springs. Dont know how much for exhaust. They do good work as I have been there a couple of times and know a few people who have been there. They are a trusted work shop.
2013 Bmw M5-Alpine White/Black-Oem gloss blk powder coated wheels-Expel clear bra-35% tint-Rpi Gtm Exhaust-Rpi Downpipes-Rpi Scoops-Halim Cazimi Performance Tune-KwV3 coilovers