Where can I go to make an informed purchase of used cell phones in St Catharines?

My husband and I grabbed a used mobile phone a few days ago for our granddaughter. She has been asking us for a new Samsung Galaxy Note and we thought it would make a great Birthday gift. We went into MTX on Merritt in St. Catharines to look for one . MTX had a variety of Samsung phones for sale and happened to have one Note 3 available. We grabbed the Samsung Galaxy Note and were given a 90 day warranty. The staff also assisted us in choosing a case and screen protctor. We were very happy with the quality of service we received and we are extremely excited to see her face when she opens her gift Thank you MTX staff