So I've been using Profit Spy for about 2 months now and I can't believe I ever tried retail arbitrage without it. I was spending a ton of time trying to find products to dropship from Amazon (mostly), Walmart (occasionally), Ali Express (a few).
What this software does is actually hunt down bargains on Amazon that you can instantly relist on eBay for instant income. It hunts down and tracks all items that have $5 - $25 profit margins, which is incredible. Saves you hours worth of time doing it yourself. It also comes with Amazon price update notifications, ebay previous items sold history, export to excel, etc.