For regular sale and giving you hopefully a nice distraction:
Splinter's Mazes E-bookFor the general public I'd say: includes mazes from easy to (extremly) hard, but for the people here the latter can be better understood as 'quite hard' seeing the experience you have with puzzling.
Paypal payment welcome! (no need for an account, only a creditcard)
Visit:
http://www.mfave.nl/en/webshop/E_boeken ... s_mazes-44Preview also available (preview does not include the 'best mazes' (most difficult ones))
(other articles regarding mazes can be found at the overview page under my administration:
http://www.doolhoven.startpagina.nl (in Dutch; you can puzzle the site out))