I think I paid about $30-40 to do a cat-back on my 2011 Fiesta, which mounts the same as the ST exhaust. Installing is super easy, the only hard part is cutting off the old system. I also worried about rusted bolts at the cat, so I took it to a shop in case they needed to heat up the fasteners. I soaked them down with PB Blast about a week before the appointment. I was in and out of the shop in under 30 minutes. The install guy said it was the easiest cat-back systems he had ever installed. The price was cheap enough that I would have them do my ST exhaust, whenever I decide to do it.