After so many years of FFXI a lot of the old big money items are either now obsolete, or so plentiful now that demand and price has significantly dropped. However there is still nice profit to be made with a little research. As has already be mentioned, the consumables market will always be in demand, you might not be making big $$$ synths, but AH'ing fast selling items in bulk can add up quickly.
Crafting materials also seem quite stable, and so with a decent HQ rate, playing sensible and farming/buying your mats from an NPC you can make a nice penny off those.
The days of hyper inflation and capping your gil with a 100 craft are long gone, but you can still make enough to get by relatively comfortable, just remember the key nowadays is crafting smart.
I recently returned after a year long break, and I've noticed that leveling a craft, woodworking in my case, has become challenging at certain steps. Nobody makes fletchings or arrowheads anymore, and arrows are a great way to skill up. I ended up having to resort to sending tells to the people in the sales history for the items I need and thankfully they were all more than willing to craft for a guaranteed buyer. I only needed to get to level 73, at that point fixing my broken Lu on all these Lik and Gugrusaurus will take me the rest of the way
It probabally varies from server to server, but I just started levelling WW for the same reason. And I was surprised at how quick and easy it was compared to other crafts I have levelled. Heck it was also quite profitable, most of my synth choices to 70 were either profit or break even.
Arrowheads on my server seemed in good supply (Maybe I got lucky and skilled my WW at the same time another player was skilling on arrowheads). As for fletchings I have no idea as to availability, I had 97 Clothcraft (Now delevelled to 89) and so could make my own.