First off, I hope u frequent headfi.org, there's an entire site dedicated to earphones.
Custom ear molds were in the realm of high-end, say bye-bye to usd$1,000 to get it done, and then of course the Asians (master copiers) said, hey we can do that with much less! But my guess is, the Asians skip that step where a true audiophile$ vendor would test which materials are appropriate sonically as well as for durability.
Once again, we are talking about a Ferrari vs a souped-up Honda. At $1/4, the Asians are not magicians.
Solution: FREE. Explanation: I will have to charge$ you.