I was just looking in to getting a kit recently, so let me share what I know.
First off, make sure it will fit without removal of the bumper supports. I was looking in to getting either the Street Fyghter 2 or C West kit, but I did some further research, and found that neither of them fit without removal of the bumper supports. I just emailed a few placest that was selling them and asked if they knew anything, and a few people emailed me back saying you had to remove the supports, so first and foremost you need to make sure you dont have to remove those, cus if you do remove them and you get in an accident, you put your ow life at risk, and youre car will be fucked up for good in even the most minor accident.
About the cost, if you dont think you can install the pieces yourself, a shop shouldnt charge more than $100 to put in for you, but its really not that hard to install it, so as long you get a good quality kit, you should be good to go there. wingswest.com has some very informative tutorials on how to install kits if you wanna go that route.
The paint is where it gets expensive. I got quotes from mutiple shops, and all of them quoted me around $400-$500 to paint the 4 pieces. If you are brave enough, you can buy a spray gun and set up your own paint booth and paint them yourself, there is a really good thread on here on how to paint your car. If you do it carefully, Im sure this would turn out really well.
If you have any other questions, just PM me.