Case #1
I'm currently waiting on a cel I purchased, for which the negotiations took most of the summer. Not an expensive cel, mind you, only $25. Still.
This was originally up on eBay, but I missed the auction and got in touch with the seller to see whether she was planning on relisting. Some time later I heard back from her. She wasn't planning on relisting at that point, but she'd be happy to sell it to me.
So... off goes the PayPal some three weeks ago.
After a week and a half or so had passed, I wrote to inquire about the status of things... which is my standard operating procedure. About this time last week I got a reply. "Oh" she says, "my mother had to go to the hospital and I totally forgot about all of my own stuff. I'm planning on taking the day off Friday to do that sort of thing. So sorry."
"No problem," says I, "but please send me a tracking number."
I didn't hear anything from the seller, so on Sunday I sent a little note to inquire whether the cel had hit the mailways as planned. No reply.
No cel, no tracking, no response to emails... What would you suggest?
Case #2
Fairly expensive cel is on hold at the Rubberslug shop. I made a downpayment of $100 in mid-August; and because this person could not accept credit card payments from PayPal I wanted to wait until my paycheck hit the bank to pull the rest out in "cash," as it were.
Because it's a pretty large sum, though, I figured I'd double-check with the seller before I sent it.
It's now a week since I sent the FIRST "are we good to go?" email to the seller. I've followed up with two others, both through regular email and the feedback system over yonder.
How long is too long? Do I start procedures to reverse these payments with PayPal?
I've never had this happen before. The weirdest thing was when a cel took a five-week-long detour courtesy of mixed up mailing labels, and even that worked out ok. I don't want to come across like a twerp, but there are other things I could do with those funds... like give 'em to the Red Cross, or the Lynxa no Pantsu fund!

Advice? Experience?