About chinese mold
If your molds are for automotive parts or high-quality medical or cosmetic parts, I suggest finding some medium or large mold-making company, even if they quoted a high price. Because they always have high-precision processing machines and high-quality control systems.
Medium and large mold-making companies always have rich experience in making these kinds of molds. They always can find the problem with your original design and can provide the solution for that.
If your molds are for household plastic parts or some electronic parts, it is no problem to choose some small or start-up mold manufacturing suppliers. But I suggest running a small production before mold export.