Download the Amazon and Ebay Apps on your cell phone and search for the item online right from your cell phone before you decide to purchase the item.
Amazon App: It has a camera to scan the barcode and look up the item. You can also just type the UPC Bar code to find the item.
Ebay App: You need tolook up the main keywords of the item and then click on Sold Items. There can be a big difference in items people are trying to sell and items that have actually sold. Also, it is important to see how often and how many items have sold in the last month. If hardly any items have sold, then it is very possible that it will be hard to get the item to sell at a price that will make you money.
At Yard Sales: It is important that you look up the items discreetly. I try to make it look like I am texting or doing something on my phone without looking too much back and forth from the item to my phone. It makes people feel weird that you might be checking prices at their yard sale and they might want to raise the price on you.
Thrift Stores: Not a big deal to check your phone at a thrift store because the price won’t change whether you check your phone or not. They also won’t throw you out if they know you are checking prices online…. at least I haven’t yet.
Auctions: I’m not an expert with auctions, but looking up the items being sold with the Amazon and/or Ebay App to find how far up you can go and still make decent money on the item. From what I have found from auctions is that it is difficult to make money because other people know the value of the items. They may not be purchasing the item to resell it, but instead keep it for themselves.
Storage Lockers: I am interested in the concepts of purchasing a storage locker, but due to the show Storage Wars, I have heard that this has gotten quite expensive for lockers of items that end up not actually selling well enough for making decent money. I do not have any first hand knowledge of this though.