Out of my hair: Spears enters rehab

How's this for an explanation for what's been going on, then?

Britney enters rehab.
The staff slip a bill under the door during her first night.
She rings her manager; he points out that it's been a while since she had a big hit, and, what with having had to pay to keep Kevin in Ho-Hos and hookers, there wasn't enough in the bank to allow her to enjoy a full fortnight.
Britney comes out of rehab.
She shaves her head.
One of her people sticks the hair on eBay.
It sells for a million or something stupid like that.
Britney returns to rehab, confident that she can cover the bill, and secure in the knowledge that she can always flog a few pubes if she needs any extras.

Speculative and unlikely, perhaps, but as Britney heads back into rehab it's no less likely than whatever really has been going on.

Her manager has asked everyone to respect her privacy "at this time." Generally, Britney signals she wants privacy by dancing in front of cameras shaving her hair off.