Even if your skills arent capped, they will be one day, rendering the Percolator useless. Thats not worth 1.5 mil to me...especially since it cant be resold to make back some of that gil.
This is kind of a useless post because I have no tests to show whether or not Percolator is "worth it" but I did spend the past 2 nights in Abyssea using the methods outlined in Camwins thread
skilling up Sharpshot on worms. I used Percolator, Steam Jacket, Mana Jammer II, Scope, Barrage Turbine and just alternate Wind and Water Manuevers. Its a good method that I found to work quite well.
If youre at the right level to do this, try it out without Percolator and see how it goes. Id give it a shot myself but Im low on stones at the moment and want to make the most of my time in Abyssea until more build up. The method in that thread was used by PUPs before Percolator even existed and several PUPs still commented on it being quick so thats probably one of the better/faster ways to go, if you can.
Have you tried farming Percolator at all?
I just built up Zeni as PUP/NIN by taking pics of the Naul in Aby-Tahrongi (flux 3). Used that to buy a few Ob pops and ended up with a Disruptor and Percolator out of the deal. Obviously your luck might be different but Id say that this is worth a shot before you go and drop 1.5 mil on an attachment that youll never touch again once you hit cap. If you have a THF friend, drag them out to Ob with you and have them proc TH a few times to better your chances.