You know, I sat there trying to do the same sort of calculation. The quilt was a scrap quilt; apart from the borders and backing there was very little outlay in fabric, but it was very much a memory quilt. I scrounged fabric from quilting friends and many of the fabrics I'd used in other older quilts were there, including some from the first one I ever made way back in 1993. The quilt was also professionally longarm quilted by Dianne Watson in Scotland. Then there was the cost in hours of my labour. I couldn't, as you say, put a value on it (there's a whole other debate) but if I'd tried, oh gosh, the maintenance man's eyes would have popped!
What really made me laugh, was that after he'd finished apologising (and he was a real sweetie) he offered to put it through the drier for nothing as compensation. Of course, I very politely declined ...