It took me a day, plus prep beforehand. I wrote plenty on it before so won't repeat here. Search my threads. But I figure 5 hrs for a shop would be reasonable if they ran into problems. It's be easy to stuff up a cat thread, strip a stud or just not be able to figure out how to tweeze the cat heat shields from around the cat itself. Some mechanics aren't too bright. I soaked my cat sensors and turbo flange studs for a day beforehand. Putting the car into a shop will mean they won't have the patience for that. Getting the stock one out is a bitch. I've talked to plenty of exhaust shops in Perth who've grizzled about losing money on the job after quoting too low. DIY is best if you have the time and tools. I wouldn't pay ~$2000 for someone to do it, on top of the kit price. I also took out all the cat leads which takes an hour to get at and rehang after the job is done.
CP_e Standback & PNP; CP_e 3" SS Downpipe; Corksport FMIC with Top-mount K&N filter & OEM Ram CAI; Turbosmart BOV; Dashhawk; Prosport Boost Guage; JBR solid shift bushes; DBA 4000 Wiper-Slot front rotors; Hawk Ferro-Carbon HPS Street front brake pads (@ 69,000km); Sumitomo HTRZIII's in 225/45 x 18