Hello, why do you think the steering column is at fault here?
Pricing for this repair will have to come from the repair shops near you that do the work.
Use this link to find some shops near you that can help with your concern:
www.repairpal.com/repair-shops
RepairPal Certified shops can diagnose and repair your 2011 Audi A8 Quattro. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.