Longest I ever had to wait for a tracking number was a week. And that's cause the guy had to look around for a big long box to ship my item in after he got off work. But it was all good 'cause I got my item the following week. So no worries.
Actually, I forgot had to do this recently too, I sold my X68000 and was stuck a couple days hunting for a box. Finally I just bought a gigantic moving box from walmart and cut it down to a manageable size, while still proving plenty of room for padding. But when I went to ship it UPS, the buyer was close enough to get it next day via ground, so it still didn't take too long to get to him. I was pretty happy about that one.