Want to buy full retail version of Aperture v1.5 from Apple. Would prefer unregistered version but if you have already registered and are willing to sell you can transfer the license as per Apple, see below

http://store.apple.com/Catalog/US/Images/singleuser.html

3. Transfer. You may not rent, lease, lend or sublicense the Apple Software. You may, however, make a one-time permanent transfer of all of your license rights to the Apple Software to another party, provided that: (a) the transfer must include all of the Apple Software, including all its component parts, original media, printed materials and this License; (b) you do not retain any copies of the Apple Software, full or partial, including copies stored on a computer or other storage device; and (c) the party receiving the Apple Software reads and agrees to accept the terms and conditions of this License. All components of the Apple Software are provided as part of a bundle and may not be separated from the bundle and distributed as standalone applications.