Lotsa' fluff and voodoo in cartridges....much the same as cables. Not that there aren't differences that are apparent for all to hear, but they are
mostly due to inherent electrical and mechanical differences. They will work and not work, as it were, with your particular due to electrical and mechanical matches.
The price differences are not just tolerances (tho, that's a portion)....you also are factoring in hourly work, country of origin, material costs and certainly a bit of mystique (call it marketing bravado) thrown in. One of the most significant differences in cost is that of the type and orientation of the diamond stylus....the direction, or grain, determines much of the sound and cheap bushed/bonded ones are significantly cheaper than high quality nude ones.
Ditto for cantilever quality....aluminum is cheapest, then you have the exotics from gold-covered aluminum thru ruby and sapphire.
Don't know where to direct you for diagrams for the nitty-gritty....

Ciao, John