Every tourist trap in Sultanahmet charges 300-500 TRY for 45-minute "authentic" dervish performances. It's dinner theater with spinning.

Galata Mevlevihanesi Museum has actual ceremonies on Sundays at 5pm for 150 TRY. Real deal - active Sufi practitioners, not actors in costumes. The building itself is a 13th-century dervish lodge.

Most tourists don't understand what they're watching anyway and just want photos.