I just sent in my paperwork (receipts and all) for an increase to my student budget to accomodate the one-time cost of a computer (laptop) system for school. I had received some inquiries as to how this process went/is going and thought I'd place it here.
First, according to http://www.pitt.edu/~oafa/costs.html
(bottom of page) you can spend up to $3K on a computer for school and have it added to your student budget. In talking with Charmaine McCall at the Pitt Law Fin Aid office, she confirmed this applies to law students. You need to complete the form here http://www.pitt.edu/~oafa/pdf/cpcost.pdf
and send it to Charmaine with all relevant receipts attached. She will then forward this on to the main financial aid office.
And that should be all that's needed. I haven't received my student budget yet, or my exact approved loan amount, so I don't know if it worked in practice. However, as soon as I hear I will post it here. Hope this helps.