Depends what kind of LS you have, if you have any interest in any of the ks99 drops, if you need money now, etc.
KS99s are no easy task, so if you do decide that route make sure your group knows wtf they are doing. KS99 have some really uber drops, but some jobs dont get much out of them. Kinda depends what the deal is with how drops are handled.
3 ks30's can be pretty good cash, if you can find a group of people that wanna use some seals and you can trust to split evenly, you get a 1/6 share of 18ish runs, which 99% of the time is gunna equal several million gil. Can use the three sets over a length of time, depending on how much you are stretched for cash.
Or you can use three seals sets, bank on getting a v claw, and end up not getting jack shit from a bunch of mages XD
Just remember, 99 seals takes a very long time to build up, so use em wisely.