Currently have an AT&T LG Encore phone. I want to purchase one just like it and found quite a few brand new ones on Ebay. Yes, they are AT&T. Can I purchase it on Ebay and then just put my SIM card in it? or do I have to take it into an AT&T store and have them do it?
Yes, you can simply purchase the phone from eBay and immediately place your SIM card in yourself and begin using it.
Be mindful that your SIM card may be temporarily locked to your original Encore, if that was the IMEI number that you activated your SIM card with. If you've been using your phone for about six months or more, you shouldn't have to worry about it.