First

to David -- not just for his generosity this past weekend, but for the work he has done for the hobby.
Next, I totally understand (and agree with) PBJ's point ... to which I would suggest that next time he just refrain from posting. I have a bunch of trackballs available as well, but I don't post about them because I can't be bothered to ship (see below).
To those who want inexpensive trackballs, there is always menace (Hi!) who has a good source for trackballs, cleans them up and puts them up for sale with some regularity.