I did a little reading, and according to Weldcraft, the primary advantage of a gas lens is the ability to have additional stickout for access to narrow joints. Weldcraft says a gas lens allows 3-5 cfh less gas flow compared to a standard torch, all else being equal.
Based on that number, I did a little math: at 3 cfh less, compared to a 125 cf tank, that is about 1/41th of the tank. If the fill of the tank is $100 (it's not, but I'm picking a high number), you save $2.43 / tank by choosing a lens. At 5 cfh reduction, you save $4 / tank.
Cyberweld has a set of five standard collet bodies for $25, or $5 each. Meanwhile, a pack of two gas lenses is $24, or $12 each, a price difference of $7. The lenses are comparably priced for both lens and standard, so they're a wash.
In conclusion, in the best case scenario (including a wildly high estimate of gas cost and assuming the best-case reduction in gas flow), you would have to use a gas lens for two full tanks of argon before it broke even compared to a standard collet on the gas flow. In reality, the break-point is probably four refills or more. And that's probably why Weldcraft says that reduced gas flow shouldn't be the primary reason for choosing a gas lens. Because, honestly, it's probably going to be years before I go through that much argon, and in the mean time, I guarantee I'm going to be crudding up the torch and so forth. And then I've only broken even. If I keep going, I will save money at a rate of... $4 per tank-fill. Whoop-de-doo!
Well, I have the lens and I have a pack of nozzles for it, so I'm going to go ahead and use them, but I probably won't buy them in the future unless I have tight joints that I need to get into, or unless I want the increased visibility that comes with additional stickout.
