I bought a heavy duty, kind of clunky nylon holster at Lowe's. (Big nylon belt loop too)
I'm not sure of it's intended purpose, but it makes a good holster for knocking around outdoors/outdoor work, and hunting & fishing. I use it nearly as much as my Otter Box.
It's a vertical case thats a little larger than my Droid Razr, but it's heavy duty nylon with Velcro flap.
As Dan recommends, try Lowes, Home Depot, or Menard's for a thick canvas pouch. Seen some made by Dickies that are made in multiple sizes for phones, calculators, and such that construction workers can use.
If you do not need named brand items, you can often find cheap cellphone accessories on ebay, sold by Hong Kong merchants.

There may even be cell phone accessories store in your area that sells generic stuff -- probably the same stuff sold by ebay merchants. These store usually have more selections than named brand stores.
I find that in malls, there are many kiosks that sell cell phone accessories. I was unable to find a belt holster for my SGS3 in big name stores like Best Buy. The sales person at BB recommended I check out one of those kiosks and I was able to find a holster for my phone.