This was my best guess for the "305" bearing. Would need samples and validation to be sure it is the same, then target price of buyers.
The issue with sourcing parts like these is competition from low cost country suppliers. Is the market willing to pay a little more for a quality part?
Determining if a part is high quality or not is a subjective thing. The installer (rebuilder) of the transmission in this case must feel the part, check tolerances, check for excessive noise or resistance. Does it look right, feel right, can I install this and not have an issue where I have to tear the whole car apart to replace a low quality bearing because I wanted to save $10?
There also seems to be a shim issue. Can this or other bearings be used without a shim? How thick does the shim need to be for each bearing? I have no idea on this question.