This happened a few years ago. I had a client in Alaska (I could probably stop there and that would be enough) who screwed me out of a little over $30,000 in billing. I did the work. He can't pay the invoice and never will be able to. He's a crooked businessman and owes so much to so many people that I'll never see anything and have given up thinking I ever might. I lost the value of the materials but I also lost the value of a lot of hours that I could have been doing productive work for some other client who actually intended to pay for professional services. I was able to write off my hard costs.