Question re buying a cell phone on Ebay

Factual Questions
1

I need another Nokia 3360 cell phone for a backup phone and I noticed that some of these are listed on Ebay as having been purchased for use with certain plans ie “Nokia 3360 purchased for Cingular/ Verizon/ATT” etc. and are now being resold.

I want to get this phone activated for Cellular One service on the Eastern Shore of Maryland. Will these prior setups interfere with my ability to use this phone on the Cellular One network, or are all Nokia 3360s the same re cellular hardware capability so they can be programmed for any US cellular service.

2

I have just sold a phone on eBay.

Some phones are ‘locked’ so that they can only be used on a specific network (or maybe with a specific SIM) - the one I sold wasn’t, but over here(UK) you can get them unlocked at high street stores for a very reasonable sum, I’m assuming that’s the same everywhere…