Looking at an average of $200-300.
But is the best in the business
x2!!!
Theres places like ARC and CIA Engineering that will fix you broken stuff on the cheap...
But they will only fix what is broken, which leads to different date codes on the mosfets from different production batches, hell even different brands.
All these things dont work good together because some will be weaker or stronger, and when you stress the amp they will just go snap crackly pop again!
Been there, and done it many of times..
Plus Ive never seen a repair shop break off the old mosfets, solder the new mosfets to the old mosfet legs with big ol booger solder joints, and say good enough, without ever removing the amp from the heatsink! Lol
DB-R is the win!