What are you going to use the adze for?
A full sized adze, with a long handle like an axe, is/was a timber framing/log building tool. It's used to make round logs into square beams. There's also a curved blade 'gutter adze,' used for - guess what - making wooden gutters.
Then, there are the smaller, short-handled carver's adzes - both straight and curved bladed. They're used for rapid 'roughing' of large (usually three dimensional) carvings. I'd guess these are what you're interested in, although I've gotta wonder how much use you'd get from one.
What really surprises me is the seemingly exorbitant prices that vendors are asking for small adzes. $150 isn't uncommon for a adze that's been re-forged from a $15 bricklayers hammer.
I know that in the Amish country near here, the blacksmiths often make adzes in their spare time, for the extra money they bring in. If your travels take you near an Amish settlement, you might try there for a source. If you're visiting Larry, there's Shipshewana, Indiana about an hour to the South. In Pennsylvania, there's Lancaster, about a hour out of Philadelphia. In Ohio, there's Berlin/Millersburg/Charm, about a hour East of Columbus.
Okay, lotsa info, but no recommendations. Hopefully somebody else here actually uses one...