Post up a picture. I paint my self. Depends on time and labour that goes into the bumper before paint. Also if it's peppered with stone chips it could or not been painted before poorly with cheap paint kits ect. So that layer would have to come off to prevent a majority of chips in the future.

Edit.
Personally I'd stay away from the rep bumpers some are good and others are crap. Also iam not sure you can get coupe rep bumpers? Only saloon and m3?

To give you a idea of price
To paint a new/second hand one with no repairs. You removing and fitting it ect 150
few minor repairs. Gash hear and scuff there. You remove and fit ect 200
Bad damage eg a days labour in repair. 250-300