What’s a good way to buy stuff wholesale and sell on eBay if you don’t have a lot of money?

martin h asked:
Name some products and suppliers, distributors, manufacturers of products that you think would sell well and are not too expensive that could be sold for reasonable profit on eBay.
Big Lots, Ross, St. Vincent De Paul, Goodwill, Salvation Army Stores, etc. etc.
Of course, catching BIG sales like Labor Day, Memorial Day, The day [...]