Authinx has always dealt with the pro line (which was always been of a higher quality).
Seeing that they needed to find a new manufacture for the X10 line I expect the quality standard will be much better.
This alone effects the price.
Gone is the day of dirt cheep manufacturing in China though it may still be cheaper then North America that too will soon not be so.
I suspect the modules you get from Authinx to be of a higher quality then that from X10WTI.
From my experience thus far, they are more concerned with quality then quantity and the mighty dollar!
Hopefully this never changes!