Re: Bout to give up....
If I understand you intend to buy a bit of brass tubing and thread it into your decaying mya stem. If that is the plan you should be able to spend a lot less then 59USD. Assuming you can get tubing that is exactly the right size you would still need to get it threaded which is a hassle but doable or have it brazed into place.
As to buying a new stem I think you'll find that what is available is not that well built and that no bargains are to be had.
Around here food stores don't carry anything related to narghiles but when traveling in other parts of the US i've found that all the grocery stores that carry such things carry Chinese junk. If you've had more success then i'm happy for you. But, if what you got at the grocery store is a 59USD rig made in China that wore out in a year i'd say you made the wrong purchase.
The places that only sell narghile related stuff are worthy of our support because they carry things that we need that no grocery store would and they give better service and support then someone who basically knows nothing but price of bread, meat and milk.
Honestly, i'd say that it's a bad idea to shop for a narghile with a low price in mind. Instead, the fact is that you'll spend hundred or more dollars on coals and shisha within a year then you would on almost any rig and yet what you use to smoke is as important as what consumables you use. Your narghile is something that should last you at least a life time and getting something that only lasts a few years is a fools economy.