I was the previous owner of that Slurpee. I traded it to the guy that consigned it. I bought it off eBay a couple of years ago. Sadly the seller was an idiot and shipped it in an envelope. Bear in mind - the whole insides are made of glass. The top of the straw had snapped clean off and shattered into tiny fragments. I gave all the fragments to the new owner and he's done a really great job getting that repaired. I'm very pleased. I would love to have that cup back!
That Slurpee's definitely an eye-catcher. I have to say that I'm also nostalgic for the old Pepsi logo used on the other products; I think it looks way better than the logos Pepsi uses today...
I'd like to say that I can't believe anyone would be stupid enough to send a prop like that in a bloody envelope, but sadly in my experience people are often complete morons when they ship things. All the time, I get people shipping me props stuffed in envelopes or wardrobe balled up very tightly so they can fit it in a Small Flat Rate Box. Really, you can't spend $2 or $4 more to use a box, and one that's actually big enough at that? I'd gladly send them the extra few dollars it would take. And don't get me started on the people who send valuable rolled posters or flyers in those flimsy triangular boxes instead of in actual reinforced tubes. I had to buy the same Buffy "Once More, With Feeling" poster four bleeping times before I got one to arrive undamaged.
One of the worst things that annoyed me hugely is when I bought what was left of the Halle Berry Catwoman costume which Inkworks had cut up for their Pieceworks card line. The top half of the costume was surprisingly fairly intact, with only the bra cups and part of one side cut into to remove leather strips to be sliced up and carded; the rest of the top, and all the belts, straps, and metal bits were still present. I figured I could have a local leathersmith recreate the missing bits so I could make a fantastic full-torso Catwoman display. So, I was very annoyed when the seller stuffed the entire thing into a regular large Priority Mail envelope--the leather was all creased and a nice piece of comic book film history which had already been damaged suffered even more unnecessary abuse. I had to do a lot of careful work on the leather just to counteract the creasing.
Anyway: boxes. When it doubt, box it. Saving a few bucks is not worth damaging something. If you can't afford a few bucks, charge a few bucks more for the shipping price and explain to buyers why.