Just watch the sellers feedback that is the main thing, then add the shipping and what you think your going to win it for add it up compare it to your lhs. If it's used you have to ask how many tanks have been through it. Would suck to buy a truck thats had 4 or 5 gallons through even if it is cheaper by 100.00 than you lhs. I bought both mine on ebay but they were new.