Lundgren intended to sell the disks to computer refurbisher shops, this is a fact of the case. In theory, they could have found a shop he intended to sell the discs to and caught him in the act. The OP was lamenting the waste of resources that went into setting up a sting, I would imagine the time involved in the above mentioned scenario would be much greater.

Lundgren wasn't setup, he wasn't coerced into doing something illegal. He was or was planning to do it and they just called him up and asked to be a customer.

This is similar to busting people for prostitution. You can either spend extraordinary time and effort in surveillance to catch them in the act. Or you can just dress in civilian clothing and approach them.