A comparison...
On one of my shopping impulses, today I picked up WotC's Stormwrack. Nothing major, just a $35 (cover price) "environmental" book. I spent a little over an hour looking it over before I got online. The book is very well designed IMO and its kind of making me take a bigger look at Freeport now from Green Ronin. Im starting to think Ocean going seperate campaign and integrating it all to the Forgotten Realms. I really was impressed with Stormwrack (as I was with Frostburn but not as much with Sandstorm).
My point is....The $35 environmental book has everything for Players as well as DMs (Prestige Classes, Rules, Scenarios, Monsters, etc), the typical price tag, and good authors. Why would I want to pay almost 4x more for Ptolus?
I like Ptolus in concept, and I absolutely love Banewarrens (which I would love to see updated to 3.5 someday) theres no way Im paying $120 for it. A 3.5 updated version of Banewarrens would definately be a plus..... still not worth the price of admission.
Before anyone chimes in about seperate $30-40 books, Yes they are worth it to me. Picking up Stormwrack and the Freeport HC will still be cheaper than Ptolus and each can be used seperately.