What are the best Cisco switches? - Cisco Computers & Internet

According to my research, 3anetwork.com is the best saller, 54% off, 2990 USD. Contrast with other professional seller:
hardware.com: 3120 USD
cdw.com: 3853.99 USD
newegg.com: 4039 USD
I don't recommend that you buy a cheaper one from amazon, ebay or alibaba, as they aren't professional at all, and also to avoid the used switches.And 3anetwork.com is the leading Cisco networking products distributor.
http://www.3anetwork.com/cisco-catalyst-3850-switches-price_c53

best attempt i'd say if there isn't any custom programming done on the switch. is to follow this. http://www.cisco.com/en/US/products/hw/switches/ps700/products_password_recovery09186a0080133fb1.shtml

Connecting a hub or switch to the "PC" port on the back of the phone is not a recommended best practice by Cisco as the IP phone does not support spanning tree protocol.

Usually when cisco equipment behave like that, its a problem with the power module, and it's best to contact the supplier...If it's under warranty they should replace it. If it's not you may need to get a technician to open it upand check the power module

No. You will create a bridge loop. The only way to do this is if you have a smart switch capable of aggregating multiple ports into a virtual trunk.