Some thoughts.... Over the winter, I switched from comp air to nitrogen. Through a little research and asking around, I was able to buy a new 20lb bottle, a double gauge regulator, and some high pressure line from bottle to workbench for $112.50. Your better prices for equipment seem to be homebrewers and a well stocked welders shop. Most industrial gas shops here in OK cater to large volume clients and industrial operations, so the gear they have is far more pricier than I needed. A N2 refill costs exactly $12.80 here in OK which will occur once in a blue moon. Yes, over the long run of years the cost is probably higher than comp air, The aggravation and noise is the priceless factor. This is a hobby, not a Fortune 500 bottom line. Safety wise, a N2 gas bottle is just as safe as compressors. Each requires different care and feeding. Off the soapbox now!