Big-box warehouse store Costco is often compared with Walmart's Sam's Club. Both stores are places where people go to buy in bulk and save money.  But while Walmart employees are striking for higher wages and health care, Costco has some of the happiest employees in the business. Costco pays its employees an average hourly wage of $11.50 to start. After five years, they make $19.50 an hour and get an "extra check," a bonus of more than $2,000 every six months, according to Slate.  While Wal-Mart's Sam's Club starts employees at $10 an hour, they make $12.50 after about five years, ... Read More