What is my time worth??.....Nothing. When nobody is standing around offering to pay me, it is worth nothing. When I take time to build a sanding belt instead of a paying job, NOW it costs me. Unfortunately, I have not had that problem lately. I just love these people that compare every task to "how much is your time worth?". I guess the answer is: if you're not going to get paid, then just sit and don't move. Now, you are really elevating the art of not getting paid to a higher degree.
Better yet, why not take a few cheap pieces of sanding rolls and figure out a way to turn them into something useful. Cost: sanding roll - 5 cents/ft, required 4' = .20. Tyvek - free, postal envelopes. Epoxy - one app., 5 cents. So for the sum of 25 cents, and a lot of time that I'm not getting paid for, I produce a perfectly good, fully functional sanding belt that, hopefully, will come in handy for those jobs that I will be paid for.
On the other hand, since I'm not getting paid for building belts, I suppose I could just sit down, watch TV.....after I put in my order to Klingspor.