"Tell me, does it move you, Does it soothe you, Does it fill your heart and soul with the roots of rock & roll? When you can't get through it you can listen to it with a 'na na na na', Well I've been there before" -"Been There Before" by Hanson
Technically, they can be sold. What you are really buying is the present owner's release of the number. Usually it is only done for businesses, and at that most commonly for custom toll free numbers or change of business ownership for billing purposes.
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MM
That which does not kill me postpones the inevitable.
If someone is dumb enough to pay that kind of money for that phone number, they are dumb enough to receive calls from me every morning at 2 AM. I will ask for Jenny.