People always post about getting killer clearance deals on copper tubing at Lowes and Home Depot but it never happens near me. Make sure you compare apples to apples. Don't think you're getting a deal because you can get 50 feet of 3/8" OD that's cheaper than some 50 ft x 1/2" OD somewhere else. If you're building an IC for 10 gallon batches, you want 1/2" OD.