You could look at it like that, but once I sold my .0008 at .0003, I just chalked up the loss and wiped the slate clean. You are correct though, I could look at it that way too and my average would be .0006.
Mentally, I like the clean slate thing because it helps we forget about the loss and move on. I think I get that from being a tennis player. I play in tournaments and stuff. My biggest crutch has always been my mental game, not physical. I have to learn to let things go and start fresh with the next point. Otherwise, I dwell on the previous lost point and it affects my whole game.