that will vary store to store I'm sure, have seen good and bad come out of there, maybe best to look at local yelp reviews and see how your local store does
I would also like to point out, that you don't want any installer to simply "tuck in the wires". Newer vehicles have side curtains / airbags that often come out of the A-Pillar and depending on if an SUV or Sedan, B or C Pillar. Meaning the pillar trim needs removed and the wire TUCKED behind the curtain and not simply into the groove. As tucking into the groove crosses over the side curtain and can impact deployment.