I love ebay. I use Ebay all the time whether I am Buying or Selling. You have to set up an account with Paypal first (which is EBay's Bank) with a Credit Card or linked to your Checking Account/Savings Account. So you must have a Bank Account or Credit Card to use.
Click on Buying on Top & it will walk you through it
You can find really Good deals, but make sure the Seller has 99%-100% Feedback. Read their Seller Feedback. Click under Seller Feedback to read what Buyers have said about them. Make sure they are truly Reputable & Legit & make sure they are in the USA.
Sellers give different options to Bid or Buy it Now on different Items. Depending on what they choose.
Search for the Phone you like, than Change search to Price & Shipping Lowest first. This way you can find the best deal. But this way, you will most likely have to watch & wait & Bid. The Higher Bidder Wins.
Before Bidding, Make sure to Read all Information/Description before Bidding. Once you Bid & You win the Bid, you can Not Retract or Back out of the Bid. If you Win you must Pay for the Item.
If for any Reason the Phone doesn't work or you are Not Satisfied (Seller lied about Item). You can Contact Ebay for a Full Refund. There is a Buyer Protection Program where they will Return your Money Back, if Seller was Misleading or you are not Satisfied.
I hope this helps. I love, love Ebay & I use it all the time. Once you try it, you will see the benefits of it. It's similar to Amazon but no Bidding.