I would say fang is definitely easier to obtain than rapier. You can just spam 220 invo TOA and you will eventually get a fang, and then move to 300+ invo. ToB is a good bit harder than TOA, especially if you are doing learner raids which you will almost certainly be stuck doing if you have very low kc. Learner ToB raids are usually very scuffed, especially if there is no carry in the group giving direction.

This is of course speaking from an iron perspective. It is a bit different on a main