To answer your question - the service chosen to post the package as per the original advert was 1st class standard (post 1).
This service according to the Royal Mail website (http://www.royalmail.com) takes between 1-2 days for deliveries to be complete - however personal experience says that you should sometimes wait up to 4 days. Items recently sold have taken 2 days before feedback has been returned by the buyer.
Your package was posted on the 21st July (see post 11) . Therefore if the RM have met their exceptionally high standards I would say your package should be with you today (Thursday).