To glean 1 lb (450 g) of dry saffron requires the harvest of 50,000–75,000 flowers; a kilogram requires 110,000–170,000 flowers. Forty hours of labour are needed to pick 150,000 flowers. Stigmata are dried quickly upon extraction and (preferably) sealed in airtight containers. Saffron prices at wholesale and retail rates range from US$500 to US$5,000 per pound, or US$1,100–11,000/kg. In Western countries, the average retail price in 1974 was $1,000 per pound, or US$2,200 per kilogram. In February 2013, a retail bottle containing 0.06 ounces could be purchased for $16.26 or the equivalent of $4,336 per pound or as little as about $2,000/pound in larger quantities. A pound contains between 70,000 and 200,000 threads. Vivid crimson colouring, slight moistness, elasticity, and lack of broken-off thread debris are all traits of fresh saffron.