I found a great deal on ebay for a used 70 quart coleman extreme ($15). I enjoy makine high gravity beers with extract methods but would like to move to all grain. I would also like to use this cooler to brew some low gravity styles. Is this cooler too large for low gravity 5 gallon batches? I have read that you should always go with a larger cooler than you expect to use as a mash tun.