If anyone is selling an Al 80 for less than $150 they are selling it for a loss. The ones at Bill Jacksons ( I bought one) are new but around a year old. Just as good as one right off the line. As long as they have just had a storage fill and kept in a controlled enviroment they don't age. The number of fills or "cycles" is what ages a tank. Obviously if you keep them outside or abuse them they will age quicker.