The two shops I worked in provided a 30 day "adjustment/tune up"...the 30 days was honored through the riding season if the bike was purchased off season, ie winter, etc. We also provided minor adjustments for the first year and a 10% discount off of accessories usually with or right after the sale but would usually honor the discount for several weeks...well worth it to make a customer happy and keep them coming back.
We also provided basic fitting and minor adjustments...we always made it clear that coming in mid day on a super busy saturday for adjustments and fit adjustments could not be done...just too busy...
Didn't matter the cost of the bike because really the average shop sells far more $350.00 bikes than $5000.00 bikes on the average Saturday. And a customer is a customer deserving the same service.