In the worst case, you hire 100 contractors with security clearance at $10K a month for 30 days and have them transcribe 20 pages a day. Buy them brand new computers at $1000 each at some refurbed warehouse and have them beaver away. Total cost: $1.3m, including $200K to get the warehouse habitable.
And there is plenty software that turns scannable hard copy documents into searchable text files.