Sometimes it just seems people look at the skill caps of things for a guide on Synthing, however from about 95 on anything over your skill can be decent. Basically with any high level synth, to try and cap you're going to be scrambling to find materials.
I'm at 94 and have been absorbing anything that comes on the AH to synth with. I found that on my server, making a few max potions can skill up well at my level and can sell for profit. Just desynth a dragon heart and turn those into max potions. Don't want to flood the market on them as not a huge amount sell.
Also keep an eye on when people buy things, ffxiah.com is a good place to check sales dates. Obviously the weekend is when you'll want to have your stuff up by. I like to synth higher selling things on thursday or friday to place on AH and keep things on it all through sunday. Weekdays the sales of things slows down, especially cursed gear, and you're almost wasting money putting it on AH, except for King Cursed gear.
Good luck in Alchemy

.