How much does it cost to have a shop tighten a motorcycle chain?

$100 for 15 minutes of work you could have done yourself after looking in a repair manual, and using a $15 toolkit.

thats a pretty easy job and you dont need any special tools. Get a shop manual and a basic set of metric wrenches and sockets. The entire job will only take you an hour at best . Otherwise your gonna pay at least an hours shop labor at about 100 to 150 dollars an hour. 

Your owners manual comes with step by step instructions and TOOLS under the seat so YOU can do it yourself.  Unless you want to pay minimum charge rate at shop. So is $100+.  Me I bend over and do it myself just cuz I got 4 bikes.  Nothing hard about it except READING.  If you notice it is sloppy, then it is really loose. They are no different than a pedal bicycle...basically.

Worst case a loose chain can break, whip around and amputate your foot. But don't worry about doing any motorcycle maintenance. Better to wait and see what happens. And hey... you have two feet.

You had a bicycle, didn't you? You tightened  Its chain. Get the Haynes manual, it will even show you what sized wrenches..

    EDIT: Some require 25 mm or larger set of wrenches, Allens and/or Torx wrenches. Not generic tools, no, but any Hardware store and Harbor Freight has them.  Tighten adjusters Evenly, like 1/2 turn  each. until about 1/2" play at middle of chain.  When done, ride her  to dealer for inspection. If he says chain worn, save for a new one.  

    No you do Not want it to come off.  Tighten Before riding, trailer it to shop if you must.  

https://www.youtube.com/watch?v=tP29lbJWeX0

   The Harley dealer here is $140/hr. Some estimate a 1/2 hour min charge for tightening. 1 hours plus parts to replace, IF sprockets still good. If Not, $$.

  IDK what Metric wrenches charge,  here. Haven't asked in 3 years. 

Anonymous,  Everyone "ends up dead", It's  just How Soon and from What. You might die of covid in a year,  killed   crossing street, burst aortic aneurism,  pulmonary embolism, or  pancreatic hemorrhage....

If it is pretty loose it probably needs replacing, plus the sprockets.

Any motorcycle mechanics will be able to give you a quote based on labour and parts (type of chain will make a difference).

And no you don't want it to come off, that can be really bad news.

One hour labor.  Two hours labor plus chain and sprocket set if the mechanic tells you the chain needs to be replaced.

i would call and ask them

i would call and ask them