Jesus began to preach after being baptised by John the Baptist, and based on Luke's gospel John only began baptising people in "the fifteenth year of the reign of Tiberius Caesar" (Luke 3:1–2), which scholars estimate to have been in AD 28–29. Subtracting 30 years, it appears that Jesus was born in 1-2 BC.
Costco is a publicly traded company, while Sam's Club is a subsidiary of Walmart. Costco's membership fees are more expensive, but its prices are slightly lower—thanks in part to its private branded products, such as Kirkland. Costco has more stores worldwide, but Sam's Club has more stores in the U.S.
Both warehouses have their own private labels, like Kirkland Signature at Costco and Member's Mark at Sam's Club. Those private labels are cheaper than name brands, and I've found Costco to have a much greater selection of those more affordable private label items.