Is that sound gear beginning to get uncomfortable around your neck? Sure maybe it was all fine at first, but when you started adding a heavier mixer, larger recorder, a few lavalier receivers and various cables, it starts to add up in weight. You’ve already dropped a ton of money on all this gear, so why should you also need to spend the outrageous prices on accessories? An extremely basic Porta Brace harness will cost you close to $100, and 
that’s just basically straps with a logo on it. Even if you have that kind of money to spend on something so basic, you’re much better off spending it on something else, a nice steak dinner for two, perhaps?
Like many things in the film industry, there is a non-industry substitute at a much lower cost. Guess what else resembles an audio bag and usually has D-rings to attach a harness too. Go ahead, take a few minutes and think about it:
Disc Golf! Well, yes and no. First of all, who knew that was an actual sport, secondly those bags look an awful lot like a typical sound bag, and thirdly there is another far more common resemblance to a sound bag, and that’s the toolbelt. Some of the bigger tool belts have D-rings for a shoulder harness to help hold it up with heavier tools, can you guess what else this harness can be used for? Exactly.
I personally own and can vouch for the comfort of the Brown Bag Company 30290 Tool Rider GSX harness, which is only $25! It features gelled padding, breathable lining to help prevent sweat buildup, and even a suspension system! But perhaps more importantly, the front of the harness has a number of loops that can be used to attach cables or lav receivers as well as a minuscule “cell phone pocket” which is far too small for the average phone nowadays, but perfect for storing some extra batteries or cards. The only negative I have found with the harness is the length of its straps. It seems to be designed for someone well over 6 feet tall, and while it is adjustable even at the shortest setting it was still too long for me. If you (or you know someone) can sew, it’s a pretty quick fix to cut the straps and get it the perfect length.
Just make sure your bag has 4 D-rings (usually two on top, two on the bottom) or at least a place on both the top and bottom where you can attach it.