Shimano reel models from lower end to high end:
Citica, Castaic, Curado E, Chronarch, Core, Calais
The Curado would probably be considered to be top of mid-level. The D series preceded the E. a list of back models can be seen here: http://fish.shimano.com/publish/content/global_fish/en/us/index/customer_service0/Reel_Schematics.html
Have you checked the Flea Market here on the forum?