There is a reason most consumer electronics uses a wall wart: safety certification. For commercial sale of an interim which has the mains plugged straight in, you'll need to
officially meet safety standards. This means lots of design effort and several thousand dollars worth of testing. Just buying the standards can be expensive to begin with.
While certain people have been known to wink at Electromagnetic Compatibility standards (i.e. RF noise) and largely get away with it, fudging a safety certification could land you in very hot water if someone gets injured
or worse, dies.
I suggest you re-purpose the thread to: 'can people recommend some OK manufacturers of wall warts?'
You absolutely can get quality goods out of China, the trick is to find the good manufacturers who give a damn. (If you pay rock-bottom prices, you'll have a high risk of getting dangerous crap. Some really shady places send you an OK units for samples, and then send dangerous #### units for production. )
If you don't want to mess about and are willing to pay a bit (or a lot!) more, DigiKey (and Mouser, Element14 etc.) has a selection of adapters with datasheets and known manufacturers available.