there is VANITYGEN with which you can easily generate such an address yourself within some minutes.
Indeed.
Address: 1B4abbxq4u9H3wSfdVMQKLTN4hwNrNoGAy
Privkey: 5JwNgB82mbPAXuFEG6vH5NQqNFzHqmUUdsmriEoRRWjbUcnGZ8C
Address: 1NnK4w4Bcu7ZhF6qerTNCZNUnVDbZNSgay
Privkey: 5JKYm6Y7bHbRZQjFEpUjhnsL7vgsgnapx3VV3bHFkZtCB6UYevX
Address: 1Dd7oB3J2rxAkoyi1p1gnR3BywDPPqZgAY
Privkey: 5JnE8KcE3awJ6BkBNW4Hq2EAX5EtvHR6PgaHyGaYV5eFQytfrLS
Address: 1KrTy5aYqZtXcCCr4vWA4FoFUHzf7M2gay
Privkey: 5JK19N953E2KNFQXGcfJUYDKoF8zZpdGEZ3dAJbDk5KTELo2GTU
And also, there's no way to "sell" the private key to a given address. You have the privkey too, so the buyer would not risk accepting coins to that address as you can also spend them. You can sell the service of helping to generate a private key by using a setup based on elliptic curve math to generate the key together, so you don't have all the information needed to spend from the address while your customer does, but you would have to generate a new address to take advantage of that.