Another computer shop i worked in charged $90 for virus removal, but we also eventually made it policy to just reformat/reimage the drive and remove all the crap and fully update the OS. Prior to that the policy was "remove viruses, remove crapware, update OS", but we had a few customers that had machines with 30,000 viruses. I forget what the record was, but it was way up there in count. Trying to clean those machines had a marginal failure rate, enough that it was costing the owner money to have us repeatedly clean them without payment.

No one wants to tell a customer that they need to find better adult content sites, and that we won't be cleaning their machines without payment anymore!