The cost varies from shop to shop and also if it includes actual work on the bike for you as well. Most shops will NOT work on the Triumphs as they are not familiar with much other then V-twins.
I pay $30 for 2 runs - no work but I get recommendations as what to do.
When a bunch of us had them done at the NH rally a couple years ago, I believe we each paid $40, same - two runs, advice but no work.
Some shops will charge you ~$200 to dyno tune the bike for you which a lot of people pay gladly as it is dialed in as neat as can be if the operator/tuner is worth half a darn.