is launching its own paid membership service, called Walmart+. Walmart+ memberships will be available Sept. 15 and will cost $98 per year or $12.95 per month, including a 15-day free trial.While originally thought to debut in August, according to a report by Recode, Walmart has delayed the launch of its paid membership service, until now.Walmart president and CEO Doug McMillon said they have tested a membership model, reported by Business Insider.