According to the Wall Street Journal Europe on Saturday these were not costs incurred by the TSA directly. Rather it was a contractor (NCS Pearson) who was contracted to hire screeners.

Total contract cost US$300 million with up to 170 sub-contractors used including:

On-site logistics support - Eclipse events - $24m
Fingerprinting - PEC Solutions - $23.6m
English Proficiency testing - Fluency Group - $16.2m
Medical Testing - Comprehensive Health Services - $73.6m