What's the difference between Yunhe brand salt 500 and 350?

Yunhe brand ordinary refined iodized salt (commonly known as old salt or ordinary iodized salt) is 500g per package, and the retail price approved by the price department is 1.30 yuan, which has been on the market for many years. Yunhe brand green food salt (commonly known as green salt), retail price1.One package in 50 yuan, listed on July 20 12, 15.