Whoa ! ... first of all, you don't need an axa QC tool post to do most anything you are going to make 1 or 2 of on a 9 inch. i ran a 9 Logan for 3 years and made runs of a few dozen when starting my business. never missed a QC . after a little practice it only takes a minute to set your lantern cutter ... and you can buy used lantern tooling cutters for about nothing dollars.
for learning or making 95 per cent of anything at all non-production, you can also learn a whole lot by grinding those cheap tool bits yourself.
buy yourself a decent, but not necessarily expensive ... tool grinder. the shaft size should be standard for stones from a tooling house, then you can add wire brushes and polishing wheels as desired.
you won't need a 4 jaw unless you are doing odd shaped parts or finishing demanding parts made in another machine. so i would save that money for other tooling as you need it for that exact job.
check your 3 jaw before you get discouraged. plenty of you-tubes on this. a 3 jaw with 0.004 runout isn't too bad ... you just have to start with 0.005 oversize stock ( g ) . your part will finish true.
and of course, ... there is the " kid with new toy " factor .. we all know you are going to be picking up on a whim all the gadgets you think would be cool for your new machine... heh ... i am retired after 40 years of machining ... and i still watch ebay for gadgets for my SB13 ... ! ... sometimes i even find one i don't already have two of already or more rarely one i actually need ...