Can’t eat the cake and keep it.
Seriously, 25 bucks and Amazon return policy. This isn’t the most sustainable approach, but economically a rather acceptable risk. Also, does a higher price always come with better QC?
The QC control issue, goes beyond the manufacture, to the sales and support. I give my non IEM example.
I bought three Samsung dongle DACs- USB-C/A to 3.5mm stereo. One from Amazon in the UK, another from ebay, and a third from a local UK business. All three were fakes., including the one sold my Amazon. I returned the one from ebay, and got my money back, cos it was so obvious that there was something wrong with the frequency response. So obvious. and the product did not look exactly like the item on Samsung's web site.
Before I bought this dongle I read Amir's glowing review on ASR, and one well known Youtuber - Julian Krausse, who both gave high marks to the product. But I never experienced any of this.
I have since discovered that contrary to about a decade ago, today's ebay, is the wild wild west, and best avoided unless you are purchasing a very complex product that is impossible to fake, such as a computer/laptop. Dongles, as I have discovered can be faked, and are being faked.
So the product itself is only the beginning. I am aware that Amazon, can repackage returned products and resell them as new, anecdotal accounts, not sure how true, but it would not surprise me, these are products fulfilled by Amazon, from its own warehouses. Should be impossible for this to happen, without them letting the buyer know, but $hit happens. I've been sold a full size professional digital piano, which was the demo copy in the shop, and they simply packaged it and sent it to me, at home, as new - it was the last of it in the country, so I had no choice but to accept their lie, and live with it. But there was payback day. Within about 3 years, the keybed went faulty, and the store had to replace the entire keybed, which costs almost as much as the keyboard, for free.!
So the buyer also has to implement their own QC. Decide where to buy from. Amazon, Ebay, Ali-Express, Linsoul, HifiGo, Headphones.com, and in the multi-seller online stores like Ali-Express, also consider the store cos many stores sell the same product.
If a Samsung DAC Dongle can be faked, with three different copies, all fake, how farfetched is it to think that IEM's are also NOT being faked. I bought a CCA Polaris, and it was the worst thing I have ever listened to. I'm suspecting it may be fake, cos it's impossible for a standard dynamic driver device to sound so terrible, like completely distorted., totally dead on arrival.
My point being, the supply chain may have become compromised for many of these popular budget IEM's. And the fault like my Samsung fakes, may have nothing to do with the manufacturer.
We the buyers now need some wit, to avoid the risks in the supply chain. This is not just about IEM's. Any product that has become trusted, a good example being the Shure SM58 and Shure SM57 microphones, that are like the air of the music industry, everyone owns one, are also the most faked microphones. So one has to purchase these from the most trusted suppliers, whose distribution chain is watertight.