Repair cost is different on each case due to what is broken.  If you busted the ASIC it will not be cheap.  Most are in the range of $25-$250 range depend on what is broken and how many items are broken.  some are getting free repair if those unfortunate ones that experienced manufactures defect be repaired with just the return shipping, however, those are very rare as most damaged hash PCB are user caused or environment related damages. 

Also, if unit was aquired from bitmainwarranty.com warranty work is all performed locally in USA, Russia, Ukraine and Venezuela and some are cross shipped based on the nature of the damages.  (user caused damages vs defect)